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UNIVERSITY OF CALIFORNIA PUBLICATIONS 
s ‘a 
ae BOTANY 
_ Vol. 5, No. 17, pp. 457-582, 2 figures in text, plates 55-85 April 14, 1922 
eS A EAT TE 
INHERITANCE IN NICOTIANA TABACUM 
A REPORT ON THE RESULTS OF CROSSING 
ee CERTAIN VARIETIES 
ea 
WILLIAM ALBERT SETCHELL ; 
THOMAS HARPER GOODSPEED : ee 


AND 
ROY ELWOOD CLAUSEN 


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Vol. 5. 1912-1922. 


Studies in Nicotiana. “I, by William Albert Setchell. Pp. 1-86.  Saeniihieg” 
BSS) Si iets ened i dane a ete a Ee We ERS Peal Me MeeR Ree CN aNee estan Hore dn Us 8 $1.25 


1. 
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3. 


18. 


16. 


17. 


Quantitative Studies of Inheritance in Nicottana Hybrids. I, by Thomas 
Harper Goodspeed. Pp. 87-168, plates 1-28. December, 1912... 


Quantitative Studies of Inheritance in Nicotiana ote aoe by Thomas . 
Harper Goodspeed. Pp. 169-188, plates 29-34. January, 1913 220... , 


. On the Partial Sterility of Nicotiana Hybrids made with : enue as Ss 


Parent, by Thomas Harper Goodspeed. Pp, 189-198. “March, 1913~_ 


. Notes on the Germination of Tobacco Seed. I, “by Thomas Harper Good- 


Speed.2 cP ps199-222- May, LORS ose Sa a eee, oath an esata wd Sea ese Ly 


. Quantitative Studies of Inheritance in Nicotiana Hybrids. 1, by Thomas 


Harper Goodspéed. ~ Pp; 223-231. “April,/1915 222 


Notes on the Germination of ‘Tobacco Seed. IL by ‘Thomas’ Harper Good- 
speed... Pp233-248-5< dune, A915, ae Se dnatce ed ee eden 


. Parthenogenesis, Parthenocarpy and Phenospermy in N tokio by Thomas : 


Harver Goodspeed. Fp. 249-272, plate.35. July, 1915 DNS eee Sas ae 


. On the Partial Sterility of Nicotiana Hybrids made qrith KN. 84 ylvestris as a 


Parent. II, by T..H. Goodspeed and A. Hy Ayres. Pp. 273-292, plate 36. 
OCEOD SH YE DEG Soa ee ha re Geng cabs ARDEA dl Su Ul ce eae ae cise 


. On the Partial Sterility of Nicotiana Hybrids made with N. sylvestris: as & 


Parent, IIT, An Account of the Mode of Floral Abscission in the F, Species ~ 


Hybrids, by: 7. H. Goodspeed and J. N. Kendall. Pp. 293-299. November, ~ 


BB) <a ae at emir np apt ae ee ec rl ts ne Pane Pee pS ES sale 


- Phe Nature of the F, Species Hybrids between Nicotiana sylvestris and- 


05 


Varieties of Nicotiana Tabacum, with Special Reference to the Conception - 


of Reaction System Contrasts in Heredity, by T. H. Goodspeed and K, =. 
Clausen. Pp. 301-346, plates 37-48. January, 1917 ....222 2 


. Abscission of Flowers and Fruits in the Solanaceae, with Special Reference 


to Nicotiana, by John N. Kendall. Pp. 347-428, 10 text figures, plates 49- 
535 <Mrarch, LOR8 ooo a he chee acorn ep tweepe nea pee Sree 
Controlled Pollination in Nicotiana, by Thomas Harper Goodspeed and = 
Davidson. Pp. 429-434. August, 1918 oes... ccs. cccek eee thee teen cnn lane ante rseee 


, An Apparatus for Flower Measurement, by T. H. Goodspeed and BE. E. 
Clausen. Pp. 435-437, plate 54, 1 figure in text. September, 1918 maneae | 


Note on the Effects of Hluminating Gas and Its Constituents in Causing. 


Abscission of Flowers in Nicotiana and Citrus, by T. H. Goodspeed, J. M.- 


McGee and BR. W. Hodgson. Pp. 439-450. December, 1918 .. Scere 


Notes on the Germination of Tobacco Seed. IJ, Note on the Relation ‘of 
Light and Darkness to Germination, by T. eeaper Goodspeed . Pp. 451- 


455. APTI, LODQ oon cscs ateccec cence cnatchecarenennnedeconeennunge nonteyseamenaneenennaeecs eee 


Inheritance in Nicotiana Tabacum. I,A Report on the Resuits of Crossing : 


Certain Varieties, by William Albert Setchell, Thomas Harper Goodspeed, 


and Roy Elwood Clausen: Pp. 457-582, 2. figures in text, plates 55-86. - 


Apr, 1922 ooo cece laces ececcenetecnnenceeecosevaessnnecesuensashsteeenasreeseenteesseneenes ee 
Index in press. : ; 


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Ma 


Vol. 5, No. 17, pp. 457-582, 2 figures in text, plates 55-85 


Ill. 


IV. 


{) 
A | : 
_)') UNIVERSITY OF CALIFORNIA PUBLICATIONS 
; . BH IN 
Cb. BOTANY 


INHERITANCE IN NICOTIANA TABACUM 


i 
A REPORT ON THE RESULTS OF CROSSING CERTAIN 
VARIETIES > 
BY 


WILLIAM ALBERT SHETCHELL, THOMAS HARPER. GOODSPEED, 
AND ROY ELWOOD CLAUSEN 


April 14, 1922 


¥ 

: CONTENTS PAGE 

Introductonyy. wee... Mander: ee ah .. 458 
Plan. of themwotkee:.......get.-.--. Peace ee .. 466 
Angustifolia-macrophylla series............. .. . 462 
1. Parents of the angustifolia-macrophylla series . 463 
2. F, of the angustifolia-macrophylla series........ . 467 
3. F. of the angustifolia-macrophylla series.. . 469 
4. F; and subsequent generations of the Pe aiecmacropls ylla series...... 472 
a. STENOPHYLLA derivatives.......... . 475 

b. Latrroiia derivatives................ . 476 

c. LANCEOLATA derivatives............ . 478 

d. Loriro.ta derivatives . 478 

e. AURICULATA derivatives........ Ps Tce , ine . 479 

Ps. SESSHUUR OMAN G OM VATULV CSMAMMMN LS <x. .cc.d.0:/<uetee..:cesuseetdbes cy ssesde vader . 480 

5. Summary of flower color observations in F, and paneeeent beneeations 482 
6. Later sowings of F, and F; of the angustifolia-macrophylla series.. .. 483 
7. Crosses of derivatives with the parents.......0..0.....:0ccccceeseeeeeee . 487 
8. Discussion of results of the angustifolia-macrophylla series ................... _ 490 
Calycina-wirginica SOMES; -.< eee cee ee oe ene eee, .. 494 
1: Parents: of the-calycina-vimgunicaiseliesin seta. on nae neti . 494 
2. F, of the calycina-virginica series.. . 496 
3. F, of the calycina-virginica series................ Pa ae 497 
4. F; and subsequent generations of the aplleatrey virginica series. . 499 
5. Discussion of results of the a virginica series ............. 504 
Alba-macrophylla series. BAAS . 504 
1. Parents of the Gibeemaerophylan series... . 504 
2. F, of the alba-macrophylla series................. .. 505 
3. F, of the alba-macrophylla series................ ». 505 
4. F; and subsequent generations of the alba- Piero phate series.. . O07 
5. Discussion of results of the alba-macrophylla series ........ . 510 


458 Umversity of California Publications in Botany [Vou. 5 


PAGE 

VI. Generalionclusionse 2) et o..: eee 510 
1. Origin and interrelationships of varieties of Tabacwm.............00000000.-.---. 510 

2. Methodology of Mendelian analysis in Tabacwme .........cccccccccecccecccecececececsen 513 

3. Mendelianthereditivsimfabacwm.....cemees0. 2.) 516 

VIL. Summarys siege. Beteec eee ete cacnes ss oot eS peak <1. 520 
Iiterature cited!)....-...see eee Aca Oa SCC ERM sei ccensyte: ee 520 
Explanation‘of plates: ea) ets... eese.....c. cee aera: ee 522 


I. INTRODUCTORY 


The inception of the work on the various species of Nicotiana 
grown and bred in the University of California Botanical Garden 
has already been sketched in a previous number of this series (cf. 
Setchell, 1912). As stated there, the original intention was to assemble 
a collection of tobacco plants simply as a portion of the outfit of the 
Botanical Garden for general instruction and display. So great was 
the variety and evident misapplication of the names under which the 
seeds were received, however, that it seemed advisable to attempt to 
determine, as definitely as possible, the status of each plant. 

In this connection, the work of Comes, in particular, came under 
consideration and especially his views as to the origin and interrela- 
tionships of the various cultivated forms belonging to the T’abacum 
group. Comes (1899, p. 4 and elsewhere) regards the numerous eulti- 
vated forms of tobacco as having originated in various ways from 
certain fundamental varieties. He estimated that there are six of 
these fundamental varieties of Tabacum, and he supposed the large 
number of various and seemingly more or less intergrading forms to 
have arisen through the influence of the forces of acclimatization, 
adaptation, hybridization, and selection. Of these, undoubtedly, the 
greater variations have been produced and perpetuated, according to 
the ideas of Comes, through hybridization and selection. In his mono- 
graph (1899) and in his later more exhaustive treatise (1905), Comes 
has attempted to estimate just which of his six fundamental varieties 
of Tabacum have codperated in producing each one of the cultivated 
‘‘races’’ so far as known to him. 

The statements of Comes as regards the constitution of his various 
races seem to have been based on the results of morphological study 
rather than upon breeding analysis. The advisability occurred to the 
senior author of attempting to test Comes’ hypothesis by selecting 
varieties seemingly fundamental in type, and through hybridization 


1922 | Setchell-Goodspeed-Clausen: Nicotiana Tabacum 459 


and selection attempting to secure constant races exhibiting various 
recombinations of the parental characters. The work thus conceived 
has been carried out in detail in a certain few but seemingly charac- 
teristic cases. Several different crosses were made in 1909, the first 
filial generations were grown in 1910, and each year since that time 
has seen successive filial generations in the field. 

Although the Nicotrana investigations were originally designed to 
attack experimentally a comparatively simple and definite problem, 
they have since been greatly amplified in scope. At the present time 
three rather distinct lines of investigation are actively in progress, viz., 

1. Mendelian inheritance in N. Tabacum. 

2. Inheritance of quantitative characters. 

3. Studies of interspecific hybrids. 
The recent appearance of bud variations in hybrid lines favorable for 
an analytie study of that phenomenon has resulted in the addition 
of another research project. Now it has been found that, although 
seemingly distinct, progress in these separate lines of investigation is 
more or less interdependent. In particular it has been found that 
certain of the phenomena exhibited in interspecific hybrid populations 
from crosses between NV. sylvestris and varieties of N. Tabacum require 
for satisfactory analysis and explanation an accurate and detailed 
knowledge of the Mendelian differences which exist among the par- 
ticular varieties of N. Tabacum that have been used in those investi- 
gations. Accordingly in later years these studies of hybrids between 
varieties of N. Tabacum, originally designed merely to test experi- 
mentally the interrelationships existing among such varieties, have 
been directed toward a specific Mendelian analysis of the germinal 
differences existing in a selected set of varieties. ; 

With this change in emphasis has come a full appreciation of the 
difficulties of Mendelian studies in N. Tabacum. It has been very 
evident that, for the most part, the character differences among varie- 
ties of N. Tabacum do not rest upon a simple genetic basis; on the 
contrary, they often depend upon very complex and involved Men- 
delian differences; so that in segregating populations it is often im- 
possible to demonstrate the existence of definite, discontinuous char- 
acter classes. Not uncommonly the members of such populations may 
be arranged in series connecting by imperceptible differences the most 
extreme character expressions in the population. 

But although complex intergrading segregation has often been 
observed in F’,, it has not been found that such complex segregation 


460 University of California Publications in Botany [ Vou. 5 


persists in subsequent generations in the hybrid lines. On the con- 
trary, it has been found, as will become evident in a study of the ex- 
perimental material communicated herewith, that a great simplification 
occurs in the segregation in F,, and subsequent generations, and that 
continuous segregation gives way to discontinuous just as might be 
expected from Mendelian theory. By observing the segregation in 
the consecutive generations of hybrid lines which have become homo- 
zygous in most of their loci through self-fertilization, it is possible to 
obtain some idea of the Mendelian factor pairs involved in the char- 
acter contrasts and of their relations to one another. It has also proved 
possible by a few years of self-fertilization to establish stable lines 
representing recombinations of parental characters. By investigating 
the interrelations among such stable derivative lines, which obviously 
should differ in fewer factors from one another and from the original 
parental varieties than the parental varieties differ from each other, 
it would seem possible to develop an indirect mode of attack by which 
the Mendelian analysis could be refined to any desired extent. The 
original plan of the investigation, therefore, having as its purpose a 
demonstration of the possibility of securing by hybridization stable 
derivative lines representing recombinatons of characters contained in 
the parents and comparable to the numerous existing varieties of NV. 
Tabacum, has been diverted into a detailed study of Mendelian differ- 
ences among a typical set of N. Tabacum varieties. 


Il. PLAN OF THE WORK 


In the introductory paper the senior author has diseussed the fun- 
damental types of N. Tabacum, and as indicated there, has expressed 
a preference for selecting some five fundamental varieties, or species, 
as representing the basal morphological elements found, or seemingly 
to be detected, in cultivated races of N. Tabacum. There is no neces- 
sity for discussing further, at present, the reasons for preferring the 
particular types selected by us as against those of either Comes or 
Anastasia (1906), since the fundamental conceptions agree sufficiently 
well and the important thing has been to make a beginning in experi- 
mentation by using varieties which present seemingly fundamentally 
different character complexes in most characteristic form in plants 
breeding true to type in the pure line. Certain reasons for selecting 
a particular type or types will be discussed in connection with the 


1922 Setchell-Goodspeed-Clausen: Nicotiana Tabacum 461 


consideration of the various crosses. Besides the ‘‘fundamental’’ types, 
there have been selected for crossing certain other types, possibly 
fundamental, or in some eases derivative, which have been employed 
for testing the inheritance of some particular character or group of 
characters. All of these have been described in the first paper of this 
volume. 

The taxonomic problems in N. Tabacum do not appear to differ 
from those presented by many other species of cultivated plants. 
Barley, maize, oats, rice, wheat, among others, exhibit a similar diver- 
sity of forms with more or less obvious class ee tinctions: In these 
as in NV. T'abacum it appears to be an easy task to shuffle and recombine 
characters indefinitely. Clearly there can be no segregation of forms 
into distinct species on genetic grounds; the basis of speciation, if any, 
must depend either upon convenience merely or what amounts to 
practically the same thing, upon elevation of certain Mendelian char- 
acter contrasts to a higher rank in classification than others. Since 


the taxonomic problem, therefore, is not strictly a genetic one, it seems 
best to follow general usage in this respect, eerring all the poly- 
morphie assemblage of forms to the one species NV. T'abacum, and re- 
garding the several races included thereunder as varieties of equal 
rank. 

The varieties employed in this series of investigations are: WN. 
Tabacum var. alba, U. C. B. G. 30/06, previously described by Setchell 
as “‘White’’ Tobacco; NV. Tabacum var. angustifolia, U. C. B. G. 68/07, 
previously deseribed by Setchell as N. angustifolia; N. Tabacum var. 
calycina, U. C. B. G. 110/05; N. Tabacum var. macrophylla, U. C. B. G. 
22/07; and N. Tabacum var. virginica, U. C. B. G. 78/05, previously 
described by Setchell as N. Tabacum ‘‘Maryland.’’ In each instance 
the University of California Botanical Garden (U. C. B. G.) number 
contains in the numerator the accession number of the year given in 
the denominator. The varieties have in the majority of cases been 
grown in pure lines from the date of their receipt. In order to avoid 
needlessly encumbering the text with scientific names, the varieties 
“mentioned above will be referred to by their varietal designations 
only, and when reference is made to the whole group the species name 
Tabacum will be used alone. 

Three series of cultures are described in the present article: the 
angustifolia-macrophylla series, which has been derived from reciprocal 
crosses of angustifolia and macrophylla; the calycina-virginica series, 
derived in the same way from calycina and virginica; and the alba- 


462 University of California Publications in Botany [ Vou. 5 


macrophylla series, from alba and macrophylla. In the course of the 
investigations other crosses were made between different varieties of 
Tabacum and to a limited extent between other species of Nicotiana; 
but the principal attention has been paid to the three crosses noted 
above, and they and their progenies alone will be considered in the 
present paper. It may be said at this point that the different varieties 
of Tabacum cross readily with one another, giving an abundance of 
good viable seed. The hybrids are uniformly self-fertile. 

The methods of hybridization used need not be considered here, 
because they have been deseribed in detail by Goodspeed (1912) else- 
where in this series. The particular refinements of technique which 
must be employed in sowing the seed, on account of its very small size, 
have also been there described. It might be well to state, however, 
that the most refined methods doubtless will not prevent the occasional 
appearance of a stray plant in the cultures. The danger of contami- 
nation arises not only during the sowing of the seed, but also when the 
bags are placed over the unopened buds. It is very easy to include a 
few stray seeds under the bag, for their small size makes it almost 
impossible to detect them in the coarse, sticky indumentum of the 
plant. In spite of these obvious difficulties, however, the number of 
plants that have certainly been strays has been very small. Their 
rare occurrence indicates clearly that the technique employed has been 
very successful. 


III. ANGUSTIFOLIA-MACROPHYLLA SERIES 


This series has received the most attention since the parents are 
so distinctly different, and the results have consequently been more 
complex than those which have followed the crossing of any other pair 
of Tabacum varieties. As will be demonstrated below, F, seemed at 
first hopeless in its variety of segregation. Later generations, however, 
exhibited so much less, or so little variety in their segregation products 
that it was easy to obtain new permanent combinations of characters 
or ‘‘fixations.’’ Certain of its segregants have been followed out to 
F,, and have also been crossed back on the parents which they most 
closely resembled. 

Six successful crosses were made. Of these H, and H, had macro- 
phylla for the male and angustifolia for the female parent, while H,, 
H,, H,;, and H,, were reciprocal crosses. As a matter of convenience 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 463 


the generations later than F, were grown only from H, and H,, the 
larger number from H,. The predominance of H, in the later families 
selected for the continuation of the work was not, however, due to any 
especially different behavior evidenced in that particular series. 


1. PARENTS OF THE ANGUSTIFOLIA-MACROPHYLLA SERIES 


By selecting angustifolia and macrophylla for crossing, two varie- 
ties were obtained which resemble each other in height and general 
habit, but which differ strikingly in leaf and flower characters. The 
differences are sufficiently great to lead one to regard them as belong- 
ing to different species; in fact, all five Tabacum varieties selected by 
us as possibly fundamental differ sufficiently among themselves to be 
regarded as species in the Tabacum section rather than as varieties. 
It is not our intention, however, to emphasize this point, since any 
discussion would of necessity lead to a general survey of all the known 
varieties and races at present included under Tabacum. If, however, 
these five, viz., angustifolia, macrophylla, ‘Cav ie,” Maryland, and 
““Brazilian’’ (ef. Setehell, loc. cit.) could be considered by themselves 
as wild plants, it seems to us that any taxonomist of the present day 
would certainly award to each of them thejank of a separate species. 
These considerations should be borne in mind in estimating the signifi- 
eance of the results obtained through crossing. 

Angustifolia, U. C. B. G? 68/07, is a variety which has long been 
known and which is répresented in our breeding experiments by a 
pure line very closely approximating the type. It has been figured 
and discussed by one of us (Setchell, loc. cit., p. 9, pl. 7). The photo- 
graph given there is of a young plant just coming into flower and 
consequently does not represent the habit of the plant in full blossom 
or in fruit, after the full number of laterals is developed. A plant 
in the height of its vigor is represented in plate 55, figure 1. In 
stature angustifolia belongs to the low corymbose group of Tabacum 
varieties, which also ineludes the forms bred in the University of Cali- 
fornia Botanical Garden under the names calycina and macrophylla, 
and which is in decided contrast to the tall, more ‘‘racemose’’ (al- 
though these may be ‘‘ecorymbose’’ at the top) forms such as alba and 
virginica. 

In height angustifolia varies from 75 to 120 em. The central axis 
develops its corymbose panicle of short racemes first, but it is usually 
soon overtopped by the successive laterals developed basipetally, each 


464 Unversity of California Publications in Botany. [ VoL. 5 


lateral, in turn, developing a corymbose cluster of racemes, rising 
more or less above its predecessors. The result is that the whole plant 
has the short corymbose habit mentioned above. The stems and 
branches of angustifolia are comparatively slender, being much more 
slender than those of macrophylla, or those of any other of the Tabacum 
varieties except those of calycina, which are very similar. 

The leaves of angustifolia are alternate and distinctly and moder- 
ately long. petiolate. The blade of the lower leaves is ovate-lanceolate,; 
tapering above to a long, eurved point, more or less conduplicate below 
and with the rounded bases unequal. Above, the leaves are less con- 
duplicate, more so even at the base, with the petiole shorter, while the 
uppermost (bracts) become almost sessile and narrowly lanceolate even 
to almost linear in outline. The normal petiole is naked at the base 
and in the middle portion, but the base of the blade is slightly and 
narrowly decurrent along the upper portion. Occasionally a petiole 
shows a narrow wing throughout its length and at times the petioles 
of all the leaves on certain plants are more or less winged, but the 
majority of the plants have naked petioles (ef. also Goodspeed and 
Clausen, 1917, p. 306, pl. 46, right-hand figuze). The leaves of angus- 
tifolia have also a very characteristic drooping habit, much more pro- 
nounced than in any other Tabacum variety except calycina. In older 
plants, after capsule formation has well advanced, all the leaves are 
hanging obliquely downwards. 

The flower of angustifolia is distinctive and differs in details of 
shape and color from that of any other Tabacum variety, and especially 
from that of macrophylla. The general shape of the flower is that of 
all the Tabacuwm section, but the corolla is much more slender and more 
gradually infundibuliform than that of any of the other varieties re- 
ported here. The calyx is broadly campanulate, prolonged above into 
5 long, but unequal, linear-lanceolate, pointed lobes, of which one is 
longer than the remaining four and gives the calyx a zygomorphie 
appearance. The corolla is narrow and tubular below the middle, 
expanding rather gradually and evenly above into a conical infundi- 
bulum which bears the spreading, deeply 5-lobed limb at its summit. 
The length of the tube of the corolla is about 6 em. and its greatest 
diameter about 7 mm. The limb of the corolla, at first erect (opening 
bud), then horizontal, finally becomes somewhat deflexed and measures 
about 3 or 3.5 em. aeross. It is divided almost to the tube into 5 lobes 
which are ovate-lanceolate with long, narrow, tapering tips. The lobes 
of angustifolia are much longer and have narrower tapering tips than 


1922 | Setchell-Goodspeed-Clausen: Nicotiana Tabacum 465 


those of any other Tabacum variety, and in this respect are in direct 
contrast to those of macrophylla. The lobes are unequal and give a 
slight suggestion of zygomorphism to the corolla. The stamens are 
inserted on the lower portion of the ‘tube and are usually slightly ex- 
serted in anthesis. The pistil possesses the usual 2-celled ovary, long, 
slender style, and thick, slightly bilobed stigma, more or less exserted 
in late anthesis, characteristic of the genus Nicotiana. The color of 
the corolla is a light, tlrough lively, pink, much lighter than-the red of 
macrophylla. The capsule at maturity is slightly flattened longitud- 
inally, is broadly lanceolate in profile, tapers above into an acuminate 
apex, and is about 25 mm. high and 8 to 9 mm. thick. It is the most 
slender of all the capsules borne by the various Tabacum varieties 
and in decided contrast to the stout eapsule of macroplrylla. 

In plate 55, figure -1, is illustrated a plant of angustifolia at the 
height of its blooming period, Typical features of the plant are shown 
in the line drawings of plate 56. Photographs of typical leaves are 
shown in plate 58, where they may be compared with photographs of 
the leaves of macrophylla. Photographs of the flowers are reproduced 
in plate 60, where they may be compared with those of macrophylla 
and of the hybrids between these two varieties. 

Macrophylla, U. b. B. G. 22/07, has ie been discussed and 
figured by one of us (ef. Setchell, loc. cit.). The original seed was 
obtained from Comes, but the plants do not correspond to his figures 
(cf. Comes, 1899, pl. VIII) either as to habit or shape of leaf. They 
differ also from his description in these same respects. The flower, 
however, agrees, and it seems best to retain for it the name under which 
we have cultivated it. 

The habit and height of macrophylla are both very similar to those 
of angustifolia. The habit is low corymbose, the central axis bearing 
a panicle of corymbose racemes and the laterals arising one after the 
other bearing similar inflorescences and equaling or overtopping the 
central axis. The stems and branchits are stouter than those of angus- 
tifolia, however, and this, together with the broader, more solid looking 
leaves which do not droop so much as those of angustifolia, give a 
mature plant of macrophylla a much more robust appearance than is 
the case with a mature plant of angustifolia. The plant figured in the 
first number of this volume (pl. 6) was young. An older plant shown 
herewith on plate 55, figure 2, is in full blossom and beginning to ripen 
its capsules, and gives a better idea of the habit of a well grown plant. 


466 University of California Publications in Botany [ Vou. 5 


The leaves of macrophylla are sessile by a partially clasping base 
and possess two basal lobes partially clasping the stem. The general 
shape is obovate, the widest portion being above the middle. The 
leaves taper gradually to the broad elasping base below and abruptly 
to a narrow more or less acuminate tip above. The surfaces show the 
secondary veins branching at a more obtuse angle than do those of the 
leaves of angustifolia. The color of the leaves is a dark green in 
macrophylla and more of a yellowish green in angustifolia. In every 
way, then, the leaves of the two parents differ from each other as much, 
in fact, as do the leaves of many species. 

The flowers of macrophylla, while of the same general type as those 
of angustifolia, differ in details of shape and color. The flowers of 
macrophylla are about 4 em. long. The calyx is broadly ovate in pro- 
file, deeply cut into 5 broad and somewhat unequal lobes. The corolla 
tube is stout cylindrical (about 5 mm. in diameter) below, broaden- 
ing suddenly into a stout infundibulum above (about 10 mm. in diam- 
eter). The limb is at right angles to the tube, is about 23 mm. across, 
and is more or less pentagonal with 5 shallow sinuses. The color of 
the corolla is deep red fading to an almost lilae tint after anthesis. 
On the limb are 5 triangular lighter areas, one having the narrow 
apex at each sinus and the broad base at the top of the tube. In the 
much darker color, in the broader tube and stouter infundibulum, and 
in the barely appreciable lobing of the limb, the corolla of macrophylla 
is the oo that of angustifolia. In stamens and pistil, the 
flower of macrophylla shows little variation from that of angustifolia. 
y to 


The capsule of macrophylla is broadly ovate, tapering abr 
i ter, 


a mucronate tip. It is about 2 em. high and about 1.5 em. in 
contrasting very decidedly with the comparatively slender capsule 


angustifolia. 

A typical plant of macrophylla is shown in plate 55, figure 2. 
Typical features of the plant are shown in line drawings in plate 57. 
Photographs of leaves are reproduced in plate 58, where they may 
be compared directly with those of angustifolia. In plate 60 its flowers 
may be compared directly with those of angustifolia and with those of 
the hybrids. 

It has seemed best to call attention to the characters of and differ- 
ences between these two varieties, parents in the first set of crosses to 
be discussed, in order that the behavior of their hybrid progeny may 
be clear. In height and habit there is a close agreement, but in leaf, 
flower, and fruit there are sufficient differences to mark them as sep- 
arate species. 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 467 


2. F, OF THE ANGUSTIFOLIA-MACROPHYLLA SERIES 


In late July of 1909, some 7 crosses were made between angusti- 
folia and macrophylla, 6 of which, as stated above, were successful. 
H,, H,, and H,, as they were designated, involved angustifolia as the 
female plant, while H,, H,, H,,, and H,, were reciprocals. No seed was 
obtained from H,, but all the other 6 crosses gave a fair yield. The 
usual care (ef. Goodspeed, loc. cit., pp. 129-131) was taken in cleaning 
and sowing the seed. This was done in the spring of 1910, germination 
was good in all eases, and 337 plants, distributed as follows, came to 
maturity and seed bearing. The family of H, had 56, H, had 60, H, 
had 47, H, had 58, H,, had 55, and H,, had 61 plants. 

A survey of all these plants showed in general a remarkable uni- 
formity in habit. A certain amount of difference was to be detected 
on careful scrutiny, but little if any greater than that which is ex- 
hibited among a large number of individuals of one or the other parent. 
In height, F, showed exactly the same variation as the parent, the 
central axes varying from 65 to 145 em., but largely varying from 90 
to 120 em., while the laterals rose to 150 em. Some rows showed uni- 
formly higher, others uniformly lower plants, the differences probably 
being due to different soil and water conditions. The habit (see pl. 61) 
was low corymbose and the general appearange as to stoutness seemed 
more or less intermediate, between the two parents. The leaves in 
‘shape, size, etc., very closely resembled those of angustifolia. There 
was some appreciable variation in the leaves, however, aud often con- 
siderable variation on the same plant, a characteristic of angustifolia 
which has already been mentioned. Plate 59 reproduces photographs 
of different types of leaves obtained from F, plants. The blade is 

broadly elliptical ovate with the lateral veins at an obtuse angle, much 

as in macrophylla. The base is rounded, or even slightly cordate in 
some leaves, while the tip is more blunt. These characters seem, at 
least, to indicate an influence of macrophylla. The leaf, however, is 
distinetly petiolate, but the petiole is not so long as in angustifolia. 

The petiole is definitely winged and the wings are expanded at the 
base into auricles, which are often triangularly decurrent along the 
internode of the stem. This wing is usually present in all the plants 
of F,, but some leaf or leaves on a plant may lack it, and in some 
plants it is only slightly developed, or at least, is without auricles. 
The wing was from 5 to 7mm. wide on some leaves. 

The leaf of 10F,H,,P, represented in plate 62 even more closely 
resembles the typical leaf of angustifolia. The wing along the mar- 


468 University of California Publications in Botany [| VoL. 5 


gins (or edges) of the petiole is narrow and is prolonged as a slight 
ridge to the internode and is decurrent (?) or ean be traced as it bends 
sharply downwards. Such wings are, at times, found in pure bred 
angustifolia plants. This leaf, then, resembles the angustifolia leaf 
fairly closely, but differs from its ordinary expression in the more 
tapering base, in being less distinctly conduplicate, in tapering more 
abruptly toward the tip, in having shorter petioles and in having more 
of a wing on the margins of the petiole. 

The flower of F, (see pl. 60) resembles that of angustifolia more 
than that of macrophylla. The color is deep pink, decidedly of a 
deeper shade than is the flower of angustifolia, yet far from the red 
of macrophylla and in a way intermediate between the two. There 
is no trace, on the limb of the corolla of F,, of the 5 white triangle- 
shaped areas so characteristic of the limb of the corolla of macrophylla. 
The infundibulum, while possibly slightly stouter than that of the 
flower of angustifolia, is not so stout as that of the flower of macro- 
phylla. In length the flower of F, averages about 4 to 4.5 em. as 
against an average of 6 em. in angustifolia, and of 4 em. in macro- 
phylla. The tube averages about 3.5 to 5 mm. in diameter below, as 
contrasted with 2.5 to 3 mm. as an average in angustifolia and 5 mm. 
in macrophylla. ¥The infundibulum in the corolla of F,, while neither 
abrupt nor so i," at of the flower of macrophylla, is noticeably 
more abruptly enlarge@ and stouter than that of angustifolia. The 
limb of the @orolla in F, averages 2.5 to 3.25 em. in greatest diamete 
while that 


are acta broad at the base, particularly so as compared with their 
length. In general, then, the corolla of F,, while closer to that of 
angustifolia, shows by its stouter tube, more abrupt and more swollen 
infundibulum, intermediate spread of limb, less deep lobing, shorter 
and broader lobes, and deeper shade of pink, definite influences of 
macrophylla also. ; 

The capsule of F, is broader than that of angustifolia, but nar- 
rower than that of macrophylla. There is greater variability in hori- 
zontal diameter in the capsule of F,. The flower and fruit of F,, 
then, although no careful biometric study has been made, are inter- 
mediate between those of the two parents, yet incline more toward 
angustifolia than toward macrophylla. 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 469 


In general, then, a survey of F', shows throughout a series of ten 
different families a uniformity of individuals as great as that exhib- 
ited in either of the parents. Some few slight differences exist among 
individuals both of F', and of the parents which may possibly be re- 
ferred to lack of a completely homozygous conditon in the parents. 
In characters in which the two parents differ, whether in color of 
flower, quantitative corolla character complexes, capsule character com- 
plexes, or leaf character complexes, the F, hybrid exhibited through- 
out a character expression intermediate between that of the two 
parents. 


3. F, OF THE ANGUSTIFOLIA-MACROPHYLLA SERIES 


In 1911, there were selected as parents for the F, 13 plants from 
H, and 12 from H,. Twenty-one families of approximately 50 plants 
each were set out in the field. On account of the great diversity shown 
in these populations, it was found impossible to study individually 
each of the thousand plants grown; consequently particular attention 
was paid to only 5 families from each hybrid. The other families were 
gone over carefully, but nothing notably different was found in their 
behavior. All fifty plants survived in each family except in the last, 

, 11F,H,P,,, where only 48 came to maturity. There were then 
is plants of F, under more careful observation, representing both 
the eross and its ‘reciprotille with about 550 remaining for only easual 
examination. 

As might have pat expected, there was 4 ereat variety of plants 
resulting and segregation as to differences in combination of characters 
of flower, fruit, and leaf was little short of bewildering. An attempt 
was made to study and jarrange these combinations, but it was found 
to be impossible. A eareful survey, however, was nade of the popu- 
lations and a sha arate was attempted. Wome 16 fairly 
réadily separable types, based on leaf characters, were distinguished, 
but between these closely approaching types others were to be found 
of intermediate and overlapping character. One each of the types 
selected was drawn, and these drawings are reproduced in plates 63 
to 78. 

A glance at these plates, which were carefully drawn to scale, will 
show something of the nature of the combinations of characters of the 
two original parents. Type 1 (pl. 63) shows a close approximation, 
yet not an absolute reproduction, of angustifolia, while type 16 (pl. 78) 
in a similar way is a close approximation to macrophylla. The other 


470 University of California Publications in Botany [ Vou. 5 


14 types (pls. 64 to 77) are clearly intermediates approaching one 
parent more than the other, but types 12, 13, and 14 (pls. 74 to 77, 
inclusive) are decidedly different from either as to leaf, at least, and 
type 10 (pl. 72) is of another altogether different form, although all 
of these leaf shapes are connected to a greater or less extent into one 
series of more or less gently intergrading forms. 

As to the shape and dimensions of the corolla there is to be found 
a similar series of intergrading forms from the slender corolla tube 
with gradually expanding and slightly swollen infundibulum and 
deeply lobed limb of type 1 (pl. 63) to the corolla with stout tube, 
abruptly and considerably swollen infundibulum with slightly lobed 
limb of type 16 (pl. 78). In color the corollas vary from the light 
pink of angustifolia to the red of macrophylla and three shades are 
at times fairly readily distinguishable, the light pink of angustifolia, 
the deep pink of F',, and the several nuances of the red of macrophylla. 

The capsules also show various combinations from the slender 
gradually attenuated capsules of angustifolia to the stout, swollen, 
abruptly upwardly attenuated capsules of macrophylla. Both ecap- 
sules and corollas approaching one parent may be found with leaves 
more closely approaching the other parent. In stature and habit the 
plants of all the | milies were reasonably uniform and agreed in 
general in these respects*with the parents and F,, there certainly being 
no greater amplitude of?variation in _ than was to be 
found in the parental types. ' ’ 

Among the great variations, two charactérs _seemed to stand out 
fairly \clearly for, a statistical = viz., color of the 

? 


corolla ‘nd the possession, or lack, of a petiole. Numerical data: for 
these characters are given in table 1. Some ¢are was taken to obtain 
~~ © as regards ea¢h of the characters. As 
was, as noted before, possible to distinguish 
shades, or sets of shades, which were designated as light pink, pink, 


a careful 


regards color 


red. In practice, however, it was usually difficult to distinguish * 
two shades of pink from each other. The red gave very little trou 

In attempting to classify the plants of F,, with respect to type of 
leaf base, more difficulty was experienced because of the variety of 
forms which were produced and the degree of intergradation which 
existed between forms. In judging the presence or absence of petiole, 
therefore, in these populations, the classification is faulty because of 
lack of knowledge of the genetic constitution of the various distinct 
forms and those which grade into them. In table 1 the plants are 


~ 


* 


I 


1922 | Setchell-Goodspeed-Clausen: Nicotiana Tabacum 471 


thrown into the petiolate class if they were distinctly narrowed at the 
base, and whether naked or winged. 

In F,, then, there appears to be simple Mendelian inheritance in 
only one pair of the original character contrasts of the parents, namely, 
red versus pink corolla color. Here the hybrid is intermediate 
and F’, segregates sharply into pink and red in the ratio 3 pink : 1 red. 
Within the pink class there is a more or less evident segregation into 
2 pink : 1 light pink, but the shades intergrade so that no distinet line 
of demarcation exists between the classes. As respects leaf base char- 
acters, the segregation is so complex that no reasonable genetic analysis 
is possible. The numerical data for this latter character presented in 
table 1 are of value only in that they indicate a close agreement in 
segregation among F’, families, thereby furnishing a rough statistical 
demonstration of the equivalence of the several familes. The more 
definite data on leaf base characters are derived from generations 
subsequent to F,. % 


TABLE 1 v 


CLASSIFICATION OF F2 PLANTS OF THE ANGUSTIFOLIA-MACROPHYLLA SERIES 
ACCORDING TO COROLLA COLOR AND LEAF BASE G@HARACTERS. 


= a 


Corolla Color r Leaf Base 
Family Garden F 
CEU) eeonbers f d pink light pink petiolate non-petiolate 
A 11F,H2P. 12 23 14 42 7 
B 11F.H2P; 14 25 10 30 20 
Cc 11F,H.Ps 13 21 15 34 14 
D 11F.H»2P, a 21 22 35 15 
E 11F,H>Pi; 15 20 14 30 20 
F 11F.H,P, 13 28 a 32 17 
G 11F,H,P;; 12 29 8 35 ) ait 14 
H 11FHyPy 13 1 22 32 ae 18 
J LRELPs: 8 bear | io 31 17 
Kk 11 FH yPas 6 27 15 38 10 
Totals 113 240 137 339 » BY 


472 Umiversity of California Publications in Botany [ Von. 5 


4, F; AND SUBSEQUENT GENERATIONS OF THE ANGUSTIFOLIA-— 
MACROPHYLLA SERIES 


From F, of H, and H,, 20 plants were selected for further ex- 
perimentation and families of 25 were determined upon as the unit. 
In all except four, the families of 25 each were successfully raised. 
Of one of the four only 14 plants were obtained, which were all that 
germinated, while in each of the other three families 24 plants were 
reared to maturity. Altogether, then, 486 plants were raised of the 
F, during the season of 1912. It was the intention to grow from each 
of the selected types, as drawn for illustration. Fifteen of the families 
from the type parents were successfully reared, but, in some way or 
other, the seed of type 4 (10F,H,P,P,,) was not to be found, and, 
unfortunately, no note had been made as to whether or not any seed 
was produced. No complete sterility, however, was noticed in any 
members of F, of either H, or H,, and the presumption is that F', seed 
of type 4 must have been lost in har vesting. 

The variation within each family was decidedly less than that of 
the families of F,. Of the 20 families reared wholly or in part, 4 
families were rete uniform, varying in minor details only. 
Five families segrega only in coroll lor, 4 segregated only in 
leaf base characters, and “fle remaining 7 segregated both in ecoroll 
color and leaf base characters. In table 2 are summarized the de 
as to gross behavior of these families of Fr. In ‘those families grown 
in F, and subsequent generations, a definite attempt was made to fix 
the original characters of the F, type seleetion in a pure line. The 
genealogical relation of these selected lines to each other is shown in 
the chart reproduced herewith. The letters, A, B, C, etc., correspond 
to the’, family designations noted in table 1, and the sihiboxs refer 
to type sélection numbers -responding to the type illustrations in 
plate 63 to 78, or, iw the case of types 17 to 21, 7 to those 


types as described in the succeeding accounts of the later generations. 


Ww 


. 


1922)" — Setchell-Goodspeed-Clausen: Nicotiana Tabacum 473 


TABLE 2 
F; FAMILIES OF THE ANGUSTIFOLIA-MACROPHYLLA SERIES. 


No. of 
plants 
Type Garden in fam- 


os. Numbers ilies | Results in F3 


1 11F,H,P7P. 25 | Segregated both as to leaf and flower color 


2 11F.H»P3P3o 25 | Segregated both as to leaf and flower color 


3 11F.H2P3Pi4 14 | Segregated only as to leaf 


5 11F.H4PaPius 24 | Segregated both as to leaf and flower color 
Li 


6 11F,H4P2Pis 25 | Uniform except as to length and development of 
wing of petiole 


7 11 FH 2PisP.g 25 Uniform both as to leaf and flower color . 


8 | 11F.HP:Pa 25 | Segregated as to leaf only 


9 11F2HyPaPs 25. | Segregated both as to leaf and flower color 


10 11F,H,;PuP:; | 24 | Segregated only as to flower color 


11 LLFSHiP aiff 25 7 ae only as to flower color 


12 11F,HyPaP i. 25 | Segregated only as to flower color 


13 11F,H)P;P x; 25 | Segregated only as to flower color 


14 11F,H,P3P3s 25 | Segregated both as to leaf and flower color 


15 11F2H2P3Pio 25 | Uniform, slight variation in tint and lobing of corolla 


16 11F,H.P3Ps 24 | Segregated only as to leaf 


17 11F,.H4P3;P.7 25 | Segregated only as to flower color 
+ ile: ESN 


18 11 F,H4P35 P35 25 | Segregated both as to leaf-and. flower color 


th as to leaf and flower color 


19 11 F,H4P35P,s 25 | Segregated 


20 | LL Fy HyP P44 25 i niform, close to macrophylla 


21 " 11 FL HyP 41 Pos 25 | Uniform, close to angustifolia 


A714 University of Califorma Publications in Botany [ Vou. 5 


In F, primary selection for parents of subsequent generations was 
based upon the type of leaf borne by the plant, flower color being 
followed as a secondary matter. In order to systematize the discussion 
concerning EF’, and subsequent generations, six general types have been 
selected and named and the discussion of the families has been grouped 


P, 1909 a MACROPHYLLA 
Fi 1910 Hs {Ha|_— [| Ha} (Hs} (His) [Hie 
Fe io! (xe? (BC Ee a) fl] K| 


Fs i9l2 BA 
(15 


Fa 1913 [6] Gal 20 ~ [|| al 
Fs 1914 6 | 20) 2) [i2al2t 
Fe Ios cl) 02 ‘wlealer 
Fr 1916 7)[6' 6a (20/204 A2)(2al2t| 


Fig. 1.—Chart showing the relationships ‘of various families of the angusti- 
folia-macrophylla series. The ditenent FE e connected with their fem - 
parents; no seed was secured from H,. The F, family a. ions correspon 
those given in table 1, and the numbers in later generations are the type n 


under which the populations are described in the text. IF, and F; of type 1 ere 
grown in 1914 and 1915 respectively. 


under these headings. The six general types selected and the names 
given them are as follows: 

a. STENOPHYLLA derivatives. As a series these approximate very 
closely in leaf shape to angustifolia. The distinguishing feature of 
this series is the possession of a distinct, long petiole. 

b. Warioura derivatives, which are characterized by the possession 
of a broa with a_petiole shorter than that of angustifolia. The 
petiole in these #ypés is more or less winged. 

c. LANCEOLATA derivatives, Which are charaeterized by the posses- 
sion of a lanceolate leaf like that of typeqs, illustrated in plate 75. 
This is a non-petiolate form. 

d. Lortrouis derivatives, characterized by possession of lo: ayes 
with very narrow blades. The type specimen, type 12, is illu ed 
in plate 74. This also is a non-petiolate form resembling the LANCEO- 
LATA derivatives, from which it differs in the extreme narrowing of the 
blade. 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 475 


e. AURICULATA derivatives. The typical form of leaf is that of 
type 10, illustrated in plate 72. The leaf blade of this form is char- 
acterized by an abrupt éontraction of the blade at the base, nearly, if 
not quite, to the midrib. Clasping auricles, from which the name is 
derived, are usually present in this form. 

f. SESSILIFOLIA derivatives, of which the leaf of macrophylla may 
be taken as the type. These derivatives are non-petiolate, as the name 
indicates. 


a. STENOPHYLLA derivatives 


Type 1, as may be seen from the drawing of F,.(cf. pl. 63), seems 
very close to angustifolia, and had light pink flowers. There were 25 
plants of 12F,H,P,P,,, the leaves of which were carefully noted; b t 
one passed its flowering stage too early to be judged, so that the color 
of the flowers of 24 only are known. Sixteen plants had srsNoPHYLLA 
leaves very nearly of type 1, but the extent of the wing structure yaried 
somewhat. The remaining 9 had LaNcEoLATA leaves of type 14. In 
flower color the segregation ratio noted was 5 red : 19 pink.” No further 
generations of this line were grown. 

Type 17 was not selected for m7 in F,, but was a plant 
very close to angustifolia. It had, however, somewhat narrower leaves 
and deep pink flowers. © The 25 plants of 12F,H,P,.P., were uniform 
and like the F’, parent except as to flower color ; 3 were red and 22 were 
deeper or lighter pink. This line was not grown through further 
generations. 


Type 21, also, was not selected for illustration of the F, plant, but 
was chosen later for perpetuation because of its extremely close agree- 
ment with angustifolia. The F, 12F,H,P,P.,, consisted of 25 vigorous 
plants which seemed to be uniform to the finest detail and agreed in 
every respect with plants of angustifolia. There were noticed in the 
plants of this family peculiar fimbriae attached to the corolla, or split 
corollas, or, in one instance, a split hose-in-hose flower such as occurs 
at times also in pure angustifolia. This type cat ima a pure 
recombination of the characters of angustifolia. e 


Type 21 was continued through tothe sev generation and 
found to be constant i thegimiformity-6f the individuals in the several 
families. In 1913, 94 plants of F, e grown; in 1914, 85 plants of 
F,; in 1915, 10 plants of F,; and in 1916, 8 plants of F,. All these 
populations closely resembled one another as to individuals as well 


as those of the F, and the F,, parent. They are all so close to angus- 


476 University of California Publications in Botany [ Vou. 5 


tifolia as to be practically indistinguishable from it. This line may 
be regarded, therefore, as a stable derivative very closely approxi- 
mating angustifolia in all its characters. 


b. LAvTIFOLIA derivatives 


Type 2 (ef. pl. 64) approached in F, fairly near to some of the 
variations of F, (ef. pl. 62). It might be regarded as a STENOPHYLLA 
derivative possessing an unusually luxuriant development of the wing 
of the petiole, but it seems more reasonable to classify it as a LATIFOLIA 
derivative exhibiting marked narrowing at the base of the lamina, such 
as is shown in LANCEOLATA derivatives. The flower was designated as 
light pink in the notes taken at the time of flowering. The leaves of 
I’, showed segregation through a considerable range, 6 being close to 
the LATIFOLIA type of F,, 6 to the LATmoLIA type of its F, parent 
(type 2), 8 were SESSILIFOLIA leaves approaching in type those of mac- 
rophylla, and 4 were AuRICcULATA leaves of type 10. In 13 the flowers 
were noted as jight pink, in 11 as pink, and in 1 as red. No subsequent 
generations of this population were grown. 

Type 3, in F,, had (ef. pl. 65) a distinetly ovate lanceolate leaf 
with a short fairly br ‘oadly’ mar ‘gined petiole. The flowers were light 
pink. F,, 12F,H,P,P,,, amoutited to 14 gérminations age" of which 


ing plants. » 
The flowers were all the light pink color of the F, parent, agreeing 


developed, although slowly, into healthy, normal appe 


with those of angustifolia, but varying somewhat in shape and size. 
The leaves were of various shapes, 4 were distinctly petiolate, while 
10 were sessile. Of the 4 petiolate plants the petiole of 1 was naked 
and of 3 more or less winged. Of the 10 sEssinirouiA plants, 9 were 
very similar to type 11, but 1 was rather longer and narrower, although 
otherwise approaching the same general shape. No further generations 
from this line were grown. 

Typed in F, (ef. pl. 67) resembled F, most nearly, but the winged 
petiole wasson and the corolla tube slightly stouter. The flower 
color was pink’s,Of 12F,H,P,,P,,, 24 plants were grown. Of these 
like those of the F, parent, but 1 had 
Of the 24 
d flowers. 


23 had leaves almips#exaé 


This line was not grown in subsequent generations. 
Type 6 was represented in F, by a plant which resemble 
having a winged petiole to the leaf and a pink flower. It is well 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 477 


sented on plate 68. In the 25 plants of 12F,H,P.P,,, the height, 
habit, flower shape, and flower color were close to, if not identical with, 
those of the F, parent. As respects leaf base characters, 14 were 
LATIFOLIA of type 6, 4 had long, naked petioles, 3 had short, naked 
petioles, 1 had a long, winged petiole, and 4 were AuRIcULATA plants 
nearly of type 10. This seems like a considerable segregation, but the 
leaves are of only two generic types, viz., petiolate and non-petiolate. 
In subsequent generations selection was made in one line for LATIFOLIA 
leaves of type 6, and in the other for auricuLATA leaves of type 10, 
called type 6a to indicate its derivation. 

Of type 6 as thus established 100 plants of F', were grown in 1914; 
100 plants of F, (50 each from 2 different parents) in 1915; 20 plants 
of F, in 1915; and 20 of F, in 1916. All the individuals thus grown 


were constant to LATIFOLIA of type 6 as originally selected. 4 
Of AuricuLATA of type 6a, similarly, 100 plants of F, were grown 
in 1913; 94 of F, in 1914; 20 of F, in 1915; and 20 of Fy in 1916. All 


these plants were uniform and true to AURICULATA of pe 6a, very 
close to AURICULATA of type 10. In both yor have definitely 


obtained stable r oii of germi ements exhibiting char- 
ers different e parents. 
13-- 48 


F, of type 7 bei ae As (ef. pl. 69), consisted of a family of 
25 plants, all ror ous except one (P,,), which was set out in the field 


later and developed into a ‘‘runt,’’ as often happens with such later 
plantings. All the plants agreed well with one another in height and 
habit except the ‘‘filler,’’? and all agreed in inflorescence, flowers, and 
leaves. There were some variations in size and lobing of the limb of 
the corolla, indicating possibly minor segregation, but in all general 
characters there was uniformity to a large degree. The plants agreed 
well in all characters with the F., parent, and also with the F, parent. 
The color of the flower was light pink, the petioles of the leaves yaried 
somewhat in length, were distinctly and more or less roa wee’ 
and the blade was heart-shaped, at least at the base in the lower leaves 
In all respects these characters were no more var pee they were 
found to be in F,. 

Type 7 continued tobreedtrue in subsggiitttn generations. It was 
grown in 1913 (100 plants, F,) M1914 (2)families of 50 plants each, 
F,), 1915 (10 plants, F,), and 1916 (10 plants, F,). All were uni- 
form as to leaf and flower color. Type 7 is very close to the type of 
F, and to type 6 described above. It, too, evidently represents a stable 
recombination of germinal elements derived from both parents. 


478 University of California Publications in Botany [ Vou. 5 


Type 9 resembles type 5, but had in F, a very short winged 
petiole and elliptical lanceolate blade. It also had pink flowers. F,, 
12F.H,P,,P,, consisted of 25 plants, 18 of which showed LATIFOLIA 
leaves of type 9, but 7 had sEssmiroura leaves of type 14 (ef. pl. 76). 
Twenty-one had pink (or hght pink) flowers and 4 had red. No 
further generations of this line were grown. 

Type 19 was an F, plant of which no drawing was made, but it 
resembled F, (ef. pl. 62), having broadly ovate leaves with a long 
and broadly winged petiole and pink flowers. F;, 12F,H,P,.P,,, con- 
sisted of 25 plants, 6 of which had sEssmiFoLiA leaves of type 16 (cf. 
pl. 78) or nearer, perhaps, to those of macrophylla, while 19 had 
LATIFOLIA leaves of type 19. In 5 plants the flowers were a somewhat 
darker red than they were in the other 20. This line was not followed 
further. 


c. LANCEOLATA derivatives 


Type 13 is similar to type 12 described below, but the leaves of the 
F,, plant were more lanceolate and broader.and the flowers were lighter 
pink. The 25 plants of 12F,H,P,P,, were uniform and like F,, except 
in flower color. Four were red, 19 ae nd 2 — to 
light pink. The line was not grown in subsequer ae 


d. LARIIFOLIA derivatives 


Type 12, as shown in plate 74, differed very decidedly in leaf shape 
from either parent. The long linear-lanceolate leaf had the long taper- 
ing curved tip of angustifolia, but the blade tapered below, making 
practically a new type. The flowers were like those of angustifolia 
in shape but were pink. The 25 plants of F,, 12F,H,P,,P,., were 
exact duplicates of F, as to habit, leaf, and flower shape, but 10 had 
red and 15 had pink flowers of various shades, mostly dark. None 
seemed as light pink as angustifolia. 

Th the most interesting of the types carried through subse- 
quent generations, representing, apparently, a new combination of leaf 
the pink flowering F, plants was chosen for seed 


12, retained for this and its progeny, while 
j ne of re ering F’, plants 
also chosen for seed. 


Type 12, as thus limited to the pink flowered co scanty 
germination and few plants for F, in 1913. Apparently it was still 
varying slightly in color within the pink shades, although fairly uni- 


characters. 


and the designation, 
the designation, 12a, was 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 479 


form except for one aberrant (?) plant of a decidedly lighter shade. 
Two ‘‘normal’’ parents of F, gave 88 and 100 plants of F, in 1914, 
which were uniform and of a bright pink color. In 1915 F,, showed 
10 plants, and in 1916 F’, also showed 10 plants, still uniform and pink. 

Type 12a on being segregated in the second growing of F, in the 
season of 1913 yielded 100 plants of F, in 1914, uniform and of deep 
red flower color. F, of 10 plants in 1915, and_also F,, of 10 plants in 
1916, produced uniform individuals of deep red flower color. 

We find, then, in types 12 and 12a definite fixations of the Lorm- 
FOLIA type, one with uniformly pink flowers ard one with uniformly 
deep red flowers. 


e. AURICULATA derivatives 


Type 8 is represented in F’, by a plant which had a leaf with an ' 
extremely constricted base (cf. pl. 70) and deep red flowers. It isy 
not a typical AURICULATA derivative, but is included under thi hea ing 
because it resembles the members of this class more closely, tI those 
of any other. F,, 12F,H,P,P,,, consisted of 25 pla which were 
uniform in height, habit, and flower color, and in agreement with F, 
in these respects. The leave a of two distinct types, 16 

of hit ang sessnionsh 0 type 16 (ef. pl. 78), the 

#.. being near to be: i, of macr ophylla. No further generations 
‘i this line were grown. 

Type 10, as shown by the drawing (pl. 72), had a peculiar leaf, 
near to the macrophylla type, yet deeply constricted at the base into a 
narrow and extremely abbreviated structure which may resemble a 
petiole or only a deeply constricted blade. There were, however, 
auricles partially clasping the stem and slightly decurrent. The leaf 
form was that characteristic of N. Tabacum var. macrophylla purpurea 
(ef. Setchell, loc. cit.). All 24 plants of F, had the same type of leaf 
as F',, but the flowers were of three fairly readily distinguishable 
shades; 3 were red, 16 pink, and 5 light pink. F, had very dark pink 
flowers. The line was not grown in further generations. 

Type 6a is a true AURICULATA derivative which segrega ed in F, 
from an F, Lavirouia selection. Its occurrence and behavior are de- 
scribed in connection with the account of type or LATIFOLIA type 
r five generations 
it has remained constant for the auricunATA type of leaf. 


from which it segregated. Grown in the pure line 


480 University of California Publications in Botany [ Vou. 5 


f. SESSILIFOLIA derivatives 


Type 11 (ef. pl. 73) im F, gave 25 plantstin 12R9H)P2 P.=all- 
vigorous except one, but that one showed the,same characters of leaf 
and flower as the others. All 25 plants possessed a SESSILIFOLIA type 
of leaf very close to the F, parent and uniform among themselves. 
There were two distinet shades of color of the flowers, 9 red and 16 
pink. No further generations of this line were grown. 

Type 14 (ef. pl. 76), so far as F, is concerned, was one of those 
having sessile leaves of a broadly lanceolate type and pink flowers. 
There were 25 plants in 12F,H,P,P,., 24 had sEssmumrouiaA leaves of 
type 14, while one (a ‘‘filler’’) had auricuLATa leaves like type 8; 19 
had pink (or light pink) flowers, while 6 had red flowers. This line 
was not followed through subsequent generations. 

Type 15 (cf. pl. 77) was represented in F,, 12F,H,P,P,,, by 25 
vigorous plants which seemed surprisingly uniform and approached 
macrophylla very closely as to leaf and color of the flower. In the 
flower, however, the color seemed even darker than that of macrophylla, 
there were only slight traces of the white tr ‘ee markings on the 
limb, the limb was mnt Adare deeply lobed, cr tube less stout 
and with the infundibulum much less abruptly We These dif 
ences seem to indicate that type 15, which all r F, plants clo: 
resemble, is not an exact recombination representing macrophylla. 

Type 15 was represented in 1913 by two families, F, of 10 plants 
and F, of 100 plants. Both families were uniform as to individuals, 
and agreed with the F, population grown in 1912 as well as with the 
F,, ancestor of the season of 1911. As this line seemed to be constant 
and very close to, although not absolutely identical with, macrophylla, 
differing in flower shape and leaf shape to some extent, type 15 was 
considered to be a fixation and no further cultivation of it was made. 

Type 16 (ef. pl. 78), which in F, approached macrophylla very 


, by 25 plants. These were all alike and closely resembled 
in all respeets except in leaf shape. Fifteen had sEssmi- 
FOLIA leaves of{type 16 while 8 had AuricuLATA leaves approaching 
those of type . 72). This line was not grown in further 
generations. 

Type 18 is the designation given to an F fant, of which no draw- 


ing was made. It seemed close to macrophylla, but the flower color 


1922]. Setchell-Goodspeed-Clausen: Nicotiana Tabacum 481 


was pink and the leaves were more slightly attenuate at the base. 
F,, 12F,H,P,.P,,, gave 25 plants, 13 of which had the gEssILIFOLIA 
leaf of type 18; 7, AURICULATA of type 10; and 5, auricuLaTa of type 8. 
In flower color, 17 were some shade of pink and 8 red. The line was 
not grown in further generations. 

Type 20 was not selected for illustration in F,, but was a plant 
chosen because of its very close resemblance to macrophylla, coming 
even closer than type 16. The F,, 12F,H,P,,P,,, consisted of 25 vig- 
orous plants of remarkable uniformity. In height, habit, inflorescence, 
flower, color, shape, fruit, ete., the details follow those of macrophylla 
so closely as to be indistinguishable unless possibly by careful and labor- 
ious biometrie study. This type may represent a practically pure 
recombination equivalent to macrophylla, and is to be compared an 
contrasted with type 15. \ 

In 1913 two families of F,, one of 21 plants and the other of 100 — 
plants, were uniform, as were 3 families of 50 plants each of F, in 
1914. In 1914, however, a surprising thing happened. fourth 
family of F,, consisting of 50 plants, was uniform except one plant 
which had pink (instead of red) flowers at id an AURICULATA leaf ap- 
proximating type 8 or 10. It seems ii Mai this plant must have 

een an intr P, but. its seed was col under bag and grown and is 
noted below and on the pedigree chart as type 20a. The other 3 plants 
of F, whose seed was sown in 1915 gave type 20 in F, in families of 
10, 9, and 8 respectively, and in turn the seed of 4 individuals of 
‘“pure’’ type 20 gave, in 1916, uniformity in families of 10 each. 

Type 20a, which originated or intruded in 1914, in one plant of 
F, of type 20 gave in F,, in 1915, 10 plants segregating for flower 
color and probably also for leaf characters, although the notes taken 
are inconclusive on the latter point. In 1916 F, of 10 good plants 
showed uniformly red flowers, but 7 had sEsstniFoLtA leaves, 4 of which 
were decidedly contracted at the base and 3 had very short winged 
petioles (AURICULATA of type 8 or type 10). On the whole it seems 
most likely that the single plant in the F, family was ane intruder, 
>. A stray 
xplain it and 
a matter of inclu- 
macrophylla as to 


since all other families of the line have been constant si 


seed somewhere along the processes of culture wo 
its appearance is all the more incomprehensible 
sion in the pedigree of type 20, as it is so close 
seem practically identical with it. 


482 University of California Publications in Botany [ Vou. 5 


5. SUMMARY OF FLOWER COLOR OBSERVATIONS IN F, AND 
SUBSEQUENT GENERATIONS 


In tables 3 and 4 we have summarized the numerical data with 
respect to flower color inheritance in F, and in the subsequent popu- 
lations. In table 3 are assembled data with respect to the behavior 
of red flowering selections from populations segregating for red and 
pink. It will be noted that all the five selections which were made 
bred true for red flower color in the sueceeding generations. In table 


TABLE 3 
INHERITANCE OF RED FLOWER COLOR IN Fs, et seq. 


Type Numbers Garden Numbers Flower color of population 
8 12F3;H2P3Pa 25 red 
12a 14F,HyP4Py2P) J 100 red 
15 12F3HoP3Pio 25 red 
16 12F;H»P3;Ps 24 red 
20 12F3H4P4P 44 25 red 
TABLE 4 


POPULATIONS FROM PINK FLOWERING SELECTIONS OF ALL SHADES IN F; et seq. 
. i " 


[ na Flower Wor classification 
Type : Parent 
NUE Garden Numbers Color ae Pi light pink 
3 12F3H.P3Pi4 light pink estes Fonp 14 
6 12F3H4P2Pis pink ait P45) S600 
v 12F 3H» Pi3P4s light pink ation 5080 25 
12 13F,H.PaP2Ps pink socn 88 ooe5 
12 13F4H4P4Pi2P 9 pink cand 100 atoll 
1 12F3H»P7Pas light pink 5 19 (or light pink) 
2. 12F3H.P3P30 light pink 1 24 (13 light pink) 
5. 12F;HyPaPis pink 8 16 (or light pink) 
9  12F,H.PaPs pink 4 | 21 | (or light pink) 
10 | 9 12F.HPaP, pink 3 | 21 | Glight pink) 
11 "MOE 3H4P4:Po pink 9 16 (0 light pink) 
12 pink 10 15 (0 light pink) 
13 pink 4 21 (2 light pink) 
14 pink 6 19) (115 eee 
7/ pink 3 22) |) ee Meseteares 
18 * pink 8 Nie | | RAercees: 
19 12F3H4P3sP.3 pink 25 (5 darker red) 


187 (Types 2 and 19 
excluded) 


fer) 
o 


Totals of segregating populations 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 483 


4 are assembled the data from ptnk flowering selections from popu- 
lations which showed segregation into red and pink. In this table the 
populations which bred true for pink are assembled in the upper 
portion of the table, and those which showed further segregation into 
red and pink are assembled in the lower portion. Of the 18 selections 
made, 7 bred true for pink (or light pink), and 10 gave segregation 
in the succeeding generation in about the ratio of 3 pink :1 red. The 
total figures for the 10 populations—187 pink : 60 red—are in very 
satisfactory agreement with the simple Mendelian ratio. The family 
of type 19 behaved in an anomalous fashion, which may indicate mis- 
classification of the F’, parent; and the family of type 2, which showed 
only one red plant has been included among those which bred true for 
pink. Strictly ight pink selections should have given only light pink 
flowers in subsequent generations; the pink ones should all have give 
segregating populations. The evidence indicates that this iad ‘ 
be obtained if segregation-occurred for only one pair tof Mors. 
The difficulty, in part at least, appears to be the as. adi 
of modifying factors in the populations. These ae \ ip parently 
weave an effect on flower color ugh bea th Br cation into 

-_ hi ig but ni enough \t® Obscure the segregation into 

.” init % abba hee sults in Nh an approximate agreement 


.. expectation, but the breeding test clearly is necessary in order 


to determine the actual distribution of the pink individuals into their 
genetic classes. 


6. LATER SOWINGS OF F, AND F, OF THE ANGUSTIFOLIA-— 
MACROPHYLLA SERIES 


In 1916 and 1917 certain families of F, and F,, of H, were grown 
in order to reéxamine them in the light of data previously collected 
and to determine whether or not any more definite classifications gould 
be made than those stated in the preceding pages. The populations 
grown are described briefly below. & 

16F,H.P,, as the population number would indicate, _svaite sowing 
of seed of 10F,H,P, from the original F, populatio “of me, As in 
previous cases, the segregation as regards leaf sha 
as to preclude definite classification. The types previously noted for 
second generation populations were all in €vi 


ee and along with 
them practically every sort of intermediate. The height of plants 
and general habit likewise agreed with the description previously 
given. 


484 University of California Publications in Botany [ VoL. 5 


It was possible as in previous instances to segregate the plants into 
definite flower color classes. In order to make this segregation as 
accurate and free from bias as possible a special method of eclassifica- 
tion was adopted. At the height of the blooming season, single typical 
flowers were collected from each plant of a population and placed in 
vials correspondingly numbered. These specimens were then taken 
into the laboratory, where they could be classified under optimum light 
conditions. The specimens so collected could then be shifted around 
into their phenotypic classes and properly compared with each other 
and with the parent colors. The color classification thus obtained 
was individually recorded, and later the population was checked over 
in the field to insure correction of any errors of classification. The 
surprising feature of this population was a sharp, three-class segre- 
gation into red, pink, and hght pink; the reds the shade of macro- 
phylla, the light pinks almost exactly that of angustifolia, and the 
pinks intermediate between the two. Within the classes there ap- 
peared to be no significant differences in depth of shade. Two plants 
bore no flowers. The ratio obtained was 15 red : 23 pink :10 light 


pink. ; 
16F,H,P,, was likewise a sowing of the seed of one % he iin 
F, plants, in this instance of 10F,H,P,,. As respects habit, height, 
and leaf shape, there was a strict resemblance throughout of this 
population to the one described above. Flower color was studied in 
the same manner and with substantially the same results. However, 
in this population there was a shading off from pink to light pink, 
such that it was impossible to draw a sharp line between these two 
classes as was done in the previous population. The shading off was 
abrupt, but there were, nevertheless, a few plants on the border line. 
The observed ratio was 16 red : 34 pink and light pink. 

YW 1917 six I’, populations, each containing approximately 100 


nape. It was impossible, however, to study these plants as 
as might have been desired on account of conditons ob- 
- 1917. However, specimens of leaves from each plant 
preserved and these were studied and classified in 
the summer of 19 A brief account of each population follows: 

i WEEP a owing from 16F,H,P,,P,, a STENOPHYLLA 
selection. With respect tOrleat base characters the segregation was 
roughly but rather obviously ‘imto two types, a long petioled sTENo- 
PHYLLA class approximating type 1 in appearance, and an AURICULATA 


taining duri 
were pressed 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 485 


class approximating type 10. Within the sTmENopHYLLA class there 
was a variation in the amount of ‘‘wing’’ on the petiole and in the 
type of blade base, some having the abrupt base of type 1, whereas 
others had an attenuated type of blade which gradually drew in to 
the petiole. In the AuRIcULATA class there was also a variation from 
the strict form of type 10 to a type which lacked the flaring auricle 
typical for that form, and had a very short naked petiole. In addition 
to this variation in the amount of ‘‘wing’’ of the constricted class 
there was also a difference in the presence or absence of attenuation 
noted for the STENOPHYLLA class, some plants having leaves abruptly 
drawn in to the midrib, whereas others were very markedly attenu- 
ated. The difference in this respect appeared to be equivalent in the 
two distinct classes, i.e., it was independent of any difference in the 


‘“netioled’’ or ‘‘constricted’’ condition. With respect to a 
VS. AURICULATA the segregation was 66 STENOPHYLLA : 32 AURICULATA. © 


17F,H,P,,P, was a sowing from 16F,H.,P,,P,, anoth STENO- 
PHYLLA selection. The leaf classes obtained here were two, STENO- 
PHYLLA (type 1) and sEssmironiA (type 15). The segregation into 
the two classes was distinct, but, as in other populations, there was a 
great deal of yt in each class. \was attenuation of the 


egperevioustyiady in b fi) ane Som of the petioled individuals 
had distinct wings, ut hs 


reer number were naked. Some few 

individuals had very short petioles. The segregation ratio was 76 
STENOPHYLLA : 24 SESSILIFOLIA. 

17F,H,P,,P,, was a sowing from 16F,H,P,,P,,, a STENOPHYLLA 

selection. The population was remarkably uniform in leaf shape, 


which closely approximated angustifolia with minor differences. The 
straplike leaves which are a characteristic feature of the upper por- 
tions of plants of angustifolia were lacking in this population, and 
the leaf tip and distal portion of the leaf blade did not narrow so 
gradually in this population as in angustifolia. Otherwise, the char- 
acters of the plants throughout were closely similar to angustifolia. 

17F.,H.P,,P.. was a sowing of seed of 16F,H,P,,P.., a STENOPHYLLA 
selection. Of the six F, populations studied, this one exhibi 


greatest diversity in segregation. With respect to leaf base 
there were two outstanding classes, STENOPHYLLA and SES 
15), which could be separated readily. Within the sr 
however, most of the individuals exhibited a more 
dition. Within the sessiiroui class, on theother hand, most of the 
individuals exhibited more or less narrowing of the leaf base, like 


# 


486 University of California Publications in Botany [ Vou. 5 


type 14. A few of the sessile individuals, instead of exhibiting gradual 
and uniform narrowing toward the base of the leaf, were constricted 
to a degree intermediate between AuRICULATA of type 10 and SESSILI- 
FOLIA of type 15. With respect to STENOPHYLLA versus SESSILIFOLIA 
the observed segregation was 67 STENOPHYLLA : 32 SESSILIFOLIA. 

17F,H.P,,P, was a sowing of seed. of 16F,H,P,,P;, an F, SESSILI- 
FOLIA selection. The leaves throughout had the sessile type of leaf 
base characteristic of macrophylla, but there were many modifications 
of it in the population. A rough classification with respect to these 
modifications of the macrophylla type of leaf base gave the following 
results : 

On 59 plants, the leaf bases were very nearly the form typical for 
macrophylla. 

On 22 plants, the leaf bases were gradually attenuated toward the 
base, resembling LANCEOLATA of type 13 as a mean. This at- 
tenuated form of the sessile leaf was a very striking feature of 
this population. 

On 10 plants, the leaf bases were intermediate in type between 
LANCEOLATA of type 13 and the typical macrophylla form. 

On 2 plants, the base of the leaf immediately above the point of 
attachment was noticeably constricted, the leaf base thus formed 
being intermediate between the macrophylla type and AuRICU- 
LATA of type 10. , 

On 2 plants, the leaves were intermediate in constriction of the 
leaf base between the strict macrophylla type and that of the 
two plants described immediately above. 


The classification here given is presented only to show that the 
sessile type of leaf base characteristic of macrophylla is subject to a 
number of very definite modifications which probably account for some 
of the complex types of segregation observed in other populations. 

17F,H,P,,P,, was a sowing from 16F,H,P,,P,., a SESSILIFOLIA 
selection, With respect to leaf base segregation there were two dis- 
tinctclasses, SESSTLIFOLIA (type 15) and aAurIcULATA (type 10). There 
was also a marked degree of variation within the classes. Within 
lass the variation was in amount and kind of narrowing 
le toward the base. A few plants showed a condition 
AURICULATA type in this respect, whereas others 
showed a gradu tenuated form of narrowing such as has been 
noted before in other populations. Within the AuRIcULATA class most 
of the individuals instead of possessing the slight wing and flaring 


the sessi 
of the lea 
approaching t 


1922 | Setchell-Goodspeed-Clausen: Nicotiana Tabacum 487 


auricles of type 10 had short naked petioles. A few were strictly of 
type 10. The following segregation ratio was noted: 61 SESSILIFOLIA : 
27 AURICULATA. 


7. CROSSES OF DERIVATIVES WITH THE PARENTS 


In the preceding account we have pointed out that by growing 
definite hybrid selections in the pure line through a number of gener- 
ations it has been possible to establish a certain number of stable 
derivatives which represent more or less obvious recombinations of 
characters of the original parents. In a Mendelian sense, they repre- 
sent stable reorganized germinal complexes containing hereditary ele- 
ments that have been derived from both parents. Obviously such 
recombinations of Mendelian units must differ in fewer units ff 
either parental type than did the parental types from each other. 
test some of these derivatives we have crossed them with the inal 
parents, usually with the one to which they bore the eloses 
blance, in order to observe how complex a type of Perceation the 
hybrids thus obtained would exhibit as co mpoTog with that of the 
— angust ape ophylla wary In yi far as they have been 
‘studied to ‘il description of thes e hybrids and their progenies 
follows: 


SESSILIFOLIAxmacrophylla. F\, SESSILIFOLIA of type 20 was crossed 
with macrophylla giving H., type 209 x macrophyllag and H,, = 
reciprocal thereof. The derivative parent here very closely resembles 
macrophylla throughout in flower color and shape, habit, leaf shape, 
ete. 15F,H,, and 15F,H.,, two families of 50 plants each, were equiy- 
alent in every respect. The plants were very close indeed to macro- 
phylla, as is also the SESSILIFOLIA parent. The only difference readily 
observed was some variation in the amplitude of the corolla. In H,,, 
a plant with a larger and one with a smaller corolla were selected for 
pure seed. In F,, grown in 1916, one family of H,, and two families 
of H,,, of 50 plants each were grown. The flower color i 
populations was throughout that of macrophylla and the 
ters also were those of macrophylla. All three families were remark- 
ably uniform, not only agreeing with one another b 


indivduals. They all resembled closely the macrophylla type and there 
The three popula- 
tions appeared to be replicas of macrophylla throughout except that 


they were slightly more robust. 


was no definite segregation of any kind in the 


488 University of California Publications in Botany | Vou. 5 


LATIFOLIA x angustifolia. KF LATIFOLIA of type 6 was crossed with 
angustifolia giving H,,—type 69 x angustifoliag and H,,, its recip- 
rocal. The derivative parent possessed the short winged petiole char- 
acteristic of LATIFOLIA of type 6. In F, 50 plants of each cross were 
grown. They exhibited the long naked petiole characteristic of angus- 
tifolia. 

In F, two populations of 50 plants each were grown. In color of 
flowers the two populations were light pink throughout, closely cor- 
responding in this respect to angustifolia. In leaf shape the segre- 
gation was sharply into two classes: the STENOPHYLLA type of leaf 
base (long, naked petiole) and the LATIFoLIA type (shorter, winged 
petiole). There was some variation in the STENOPHYLLA class sug- 
gesting intermediacy between angustifolia and LATIFOLIA, but the forms 
exhibiting it showed a graded series from strict STENOPHYLLA to inter- 
mediate. The LATIFOLIA class was very uniform and sharply set off 
from the other class. The segregation ratios observed were as follows: 


STENOPHYLLA LATIFOLIA 
16FH52Pis 42 8 
if 6 FH 33Ps35 36 14 
Totals 78 22 |! 


AURICULATA x macrophylla. EF; AuRICULATA of type 6a was crossed 
with macrophylla giving H., and H,,—=F, type 6a x macrophyllag 
and H,, and H.,, their reciprocals. It should be observed that type 
6a is an early segregant from the LATIFOLIA of type 6 of H,, and H,,. 
In F, 50 plants were grown of each of the four parents. All four 
populations were equivalent in every respect. All the plants had pink 
flowers, although one plant had flowers of a lighter shade than the 
others, and leaves of a shape somewhat intermediate between the two 
parents, i.e., they were more contracted at the base than macrophylla, 
bufgmuch less so than those of type 6a. One plant of H,,, namely 
15F,H,,P,,, showed larger corollas than any of the other F, plants 
of any ‘family, and was selected for further breeding. 


ur families were raised and they proved to be equivalent 
except as noted. There was sharp segregation for leaf 
shape into the§esstuiroi1a and the sharply constricted AURICULATA type. 
In the sSEssmiro class there were a number of obvious intermedi- 
ates, as might be eXjected from the characters exhibited by F,, but 
they formed a continuotissseries with the strict SESSILIFOLIA forms. 
The AURICULATA class did not intergrade with the dominant class. 


1922 | Setchell-Goodspeed-Clausen: Nicotiana Tabacum 489 


Segregation for flower color was studied by the method described above. 
The color distinction between red and pink was sharp and easily drawn. 
In the pinks, however, there was a continuous series of shades from 
the deep’ rose pink characteristic of F, to the light pink typical for 
angustifolia. Numerical data are given in table 5. 


TABLE 5 H 
F2 SEGREGATION OF PINK AURICULATA X RED SESSILIFOLIA. 
Pink Red Pink Red 
Garden Numbers sessilifolia sessilifolia auriculata auriculata 

16F.H54P7 32 6 9 3 
16F2H5;Pis 23 11 lat 5 
16F2H;; Po 26 13 7 a 
16 F2H355Po5 26 11 a 2 
16F2H359.P35 26 12 on 2 
Totals 133 53 40 16 
Expected 136 45 45 15 


In 1918 in connection with flower ine yee three more popula- 
i of F.H,, Mi Ta Bere were collected from each plant 
and pressed, and leaf shape studies were made on these preserved 
specimens. The studies were not so satisfactory as those made in the 
field, where it is possible to examine all the leaves on a given plant; 
nevertheless, the data derived from the studies agreed substantially 
with those obtained in 1916 from field studies. It was noted in these 
studies that there was a distinct class of ‘‘attenuated’’ leaves similar 
to those which have been described in previous populations. Both 
attenuation and constriction were observed to occur in the leaves of 
some individuals, and this gave rise to some difficulty in classification. 
Numerical data are given in table 6. 


TABLE 6 ¢ 
F2 SEGREGATION OF SESSILIFOLIA X AURICULATA. ‘ 
Garden Numbers SESSILIFOLIA Avmrcpadera 
18F.H55P10 67 of bs 
18F.H;5P 1 79 18 
18F.H5;Pas 79 17 
Totals 225 63 


490 University of California Publications in Botany [ Vou. 5 


STENOPHYLLA x angustifolia. Reeiprocal crosses were made between 
F’;, STENOPHYLLA of type 21 and angustifolia; H,, =F, type 219 x 
angustifoliag and H.,,,, its reciprocal. SrENOPHYLLA of type 21 has been 
deseribed previously as a stable derivative closely approximating 
angustifolia in all its characters. KF, families of 50 plants of each 
hybrid were raised in 1915. They were uniform throughout and so 
close to angustifolia in all characters as to be indistinguishable from 
it. One plant seemed to be of a slightly darker pink corolla color. 
15F,H.,aP,, was the only F, family raised. The flower color of this 
population was about the shade of angustifolia and uniform through- 
out the population. The family showed only a slight variation in the 
base of the blade such as is also seen in populations of angustifolia. 


8. DISCUSSION OF RESULTS OF THE ANGUSTIFOLIA—-MACROPHYLLA 
SERIES OF INVESTIGATIONS 


Obviously the outstanding result of this series of investigations of 
hybrids between angustifolia and macrophylla is a demonstration of 
the complexity of the germinal differences which exist between the 
two varieties with respect to practically every character contrast which 
may be made between them. Only in one instance, the contrast be- 
tween the light pink flower color of angustifolia and the red of macro- 
phylla, is a simple Mendelian formulation possible. Here evidently 
the main flower color difference is dependent upon a simple allelo- 
morphie contrast. Red x light pink gives F, intermediate pink, and F, 
1 red : 2 intermediate pink :1 light pink.. The red segregants breed 
true for red, the light pinks for light pink, and pink continues to 
segregate in the typical mono-hybrid fashion. Inasmuch as the inter- 
mediate pinks and light pinks form an intergrading series, it is con- 
venient to look upon red as the recessive color. Accordingly we give 
this pair of factors the designation, Rr, following the mnemonic system 
advocated by Morgan, and shall so refer to it in what follows. The 
difficulty among the pinks appears to be due not only to phenotypic 
n but also to the existence of modifying factors which have a 
slight effeet upon flower color expression. These less strik- 
ions of flower color we are seeking to analyze further. 
iape investigations, the complexity of the results is 
an examination of the data presented in the fore- 
going pages. Althou the behavior here is complex, in every feature 
it parallels the Me ndelian expectation for complex factor relations. 


variat 


relativels 
ing modifica 

In the lea 
plainly evident fr 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 491 


In F, the variety of leaf shapes encountered was nothing short of 
bewildering and series could be built up from them showing complete 
intergradation from one type to another. Selection of phenotypes 
from F,, however, gave F., populations in which the complexity of 
segregation was usually reduced in a very definite fashion. Most of 
the populations exhibited fewer classes than F’,, and the selection of 
F, phenotypes held the expression of F, within very definite limits. 
Thus selection of SESS™IFOLIA forms gave in F, either all SESSMmIFOLIA 
or approximately 3 SESSILIFOLIA :1 AURICULATA. In no ease did such 
selections give F, populations with STENOPHYLLA or LATIFOLIA leaf 
types. A summary in detail of the type of populations produced is 
as follows. 

STENOPHYLLA selections may segregate in a variety of ways. Thus, 
type 1 showed approximate segregation into 3 STENOPHYLLA : 1 SESSI- 4 
LIFOLIA. Type 21 bred true to the STENOPHYLLA characters. Anondll 
STENOPHYLLA selections grown in 1917, population 17F,H,P,,P,, 
showed approximate segregation into 3 STENOPHYLLA : 1 ae. 
17F,H,P,,P,, 3 STENOPHYLLA:1 sSESstLIroLIA; 17F,H,P,,P, bred true 
for STENOPHYLLA, and 17F,H,P,,P,, gave a rather indefinite segrega- 
jon of approximately 3 STENOPHYLLA % \sessmironiA. Larrronta 
ee vas crossed with angustifolia gave F, srenopryiia and F, 
approximately 3 STENOPHYLLA : 1 LATIFOLIA. 

LATIFOLIA selections also segregate in perplexing fashion. The F, 
population of angustifolia x macrophylla is typically LATIFOLIA in its 
characters. LariroutA under certain conditions therefore 1s a very 
complex hybrid expression. Recurrence of complex segregation of a 
LATIFOLIA selection is shown in F, of type 2. F., of type 3 exhibited 
a rather anomalous segregation ratio of petioled and sessile forms. 
Type 5 apparently bred true, although there was one anomalous plant 
in the population. Type 6 exhibited complex segregation, with an 
indication of a ratio of 3 LATIFOLIA :1 AURICULATA; with subsequent 
establishment of both LAaTrrOLIA and AURICULATA In constant races. 
Type 7 bred true for a type of leaf hke F,; and type 9 gave approxi- 
mate segregation of 3 LATIFOLIA : 1 SESSILIFOLIA. 

LORUFOLIA and LANCEOLATA derivatives are really varia 
SESSILIFOLIA type. They were both produced in constan 


s of the 
s. Their 
ll established 
y are really quan- 


genetic relation to the other forms is, however, no 
by this series of investigations. Although these 
titative variations from the strict SESSILIFOLIA.type, nevertheless, cer- 
tain of our-data indicate discontinuous inheritance of these contrasts. 


492 University of California Publications in Botany 1 VoL. 5 


The same quantitative factors that differentiate the narrow-leaved forms 
of SESSILIFOLIA from the typical broad-leaved forms may apparently 
differentiate narrow-leaved STENOPHYLLA, LATIFOLIA, and AURICULATA 
forms from the more typical broad-leaved ones. It is of interest in 
this connection to note that LORUFOLIA derivatives have much nazrower 
leaves than either of the original parents. 

We have been especially interested in these LORIMFOLIA derivatives 
beeause they are somewhat like the narrow-leaved forms that Hassel- 
bring (1912) found among Cuban tobaccos, and which are so well 
recognized among Cuban growers as to have received the specific desig- 
nation of lengua de vaca or ‘‘cow’s tongue.’’ Our results indicate 
that it is possible for such forms to arise by segregation from crosses 
between broader leaved forms. The lengua de vaca of the Cuban 
growers is, therefore, probably a segregation product which could 
easily be eliminated by the adoption of proper pure line methods of 
breeding. 

Avricuuata forms appear to breed true whenever segregated. The 
exception is type 8, which requires further investigation. It may be 
a leaf type similar to AURICULATA but of different genetic constitution. 
AURICULATA of type 10 bred true in F,. The AuricunaTa form 6a, 
which segregated from type 6 bred true thereafter. AURICULATA 
crossed with macrophylla, H.,, H;;, H;;, and H;, gave SESSILIFOLIA in 
F, and in F, 3 SEssILIFOLIA : 1 AURICULATA. 

SEsSILIFOLIA forms have broad sessile leaves, the distinguishing 
feature being merely their sessile mode of attachment. Of such selec- 
tions from the original F,, populations, four, with the exception of one 
anomalous plant, bred true for susstuiroutA. Each of the other three 
populations segregated into SESSILIFOLIA and AURICULATA In about the 
ratio of 3 SESSILIFOLIA :1 AURICULATA. Two SESSILIFOLIA selections 
were grown in 1917. One of these bred true to SESSILIFOLIA ; the other 
gave 3 SESSILIFOLIA :1 AuRICULATA. The behavior of SESSILIFOLIA in 
relation to STENOPHYLLA and LATIFOLIA is explained above. 

On the basis of these results we may distinguish certain definite 


allelomérphie pairs of factors as follows 


JOPHYLLA versus SESSILIFOLIA: SS being long petioled like 
and ss broadly sessile like macrophylla. The heterozygote 
roach an intermediate condition similar to LATIFOLIA. 
versus LATIFOLIA: LL being long petioled like 
angustifolia, and ll Short petioled like LatironiA and with a distinet 
but not broad wing. The contrast is really one of SSLL, stENOPHYLLA 


may possibly 4 
Ll, stENOPHY 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 493 


versus SSI], LatmourA. Both ssLL and ssll are probably typical sEsst- 
LIFOLIA forms. Here again the heterozygote probably shows an indis- 
tinet type of intermediacy. 

Aa, SESSILIFOLIA versus AURICULATA: AA having the broad clasp- 
ing leaf base characteristic of macrophylla, and aa the deeply con- 
stricted leaf bases with flaring auricles characteristic of AURICULATA. 
The contrast here is really one of ssAA, SESSILIFOLIA versus SSaa, AURI- 
CULATA, for these factors are evidently latent when in combination with 
SS or Ss. 


Fig. 2. Leaf base types of the angustifolia-macrophylla series. Left to right: 
STENOPHYLLA, LATIFOLIA, SESSILIFOLIA, and AURICULATA. 


Some of the possible genotypes, their phenotypic expression, and 
genetic behavior are included in table 7. Here only monohybrid segre- 
gation is considered because it is doubtful, on account of the various 
types of intermediacy shown by heterozygotes, whether it would be 
possible to classify dihybrid and trihybrid populations satisfactorily. 


TABLE 7 
GENETIC BEHAVIOR OF VARIOUS LEAF TYPE GENOTYPES. 


Genotype Phenotype Genetic behavior 
SSLLAA STENOPHYLLA Breeds true 

SsLLAA STENOPHYLLA 3 STENOPHYLLA : 1 SESSILIFOLIA 
SSLIAA STENOPHYLLA 3 STENOPHYLLA : 1 LATIFOLIA 
SSLLAa STENOPHYLLA Breeds true vd 
SsLLaa STENOPHYLLA 3 STENOPHYLLA : 1 AURLEULATA 
SSIIAA LATIFOLIA Breeds true 

SsIIAA LATIFOLIA 3 LATIFOLIA ESSILIFOLIA 
Ssllaa LATIFOLIA 3 LATIFOLIA #1 AURICULATA 
ssLLAA SESSILIFOLIA Breeds true , 

ssllAA SESSILIFOLIA Breeds trué 

ssllAa SESSILIFOLIA 3 SESSILMPOLIA : 1 AURICULATA 


ssllaa AURICULATA Breeds true 


494 University of California Publications in Botany [ Vou. 5 


Although intermediacy of the heterozygote appears to be the normal 
thing in these leaf shape contrasts, it is proper to state that this inter- 
mediacy may depend to some extent upon the effect of modifying 
factors rather than upon the heterozygous conditon of a pair of allelo- 
morphs. Thus the intermediate conditon between STENOPHYLLA and 
AURICULATA is met with in populations which do not contain AURICU- 
LATA segregation products. There are so many modifying factors in 
this series of investigations that it is probably impossible for us to 
declare definitely that in any one instance our observed segregation 
was wholly the result of segregation of one pair of allelomorphs. 
Further investigations are in progress, the purpose of which is to 
isolate and evaluate, if possible, certain of these subsidiary factors. 
For the present we can only state our certain knowledge of their 
existence, and our belief as to their various effects. 


IV. CALYCINA-VIRGINICA SERIES 


The calycina-virgimea series of hybrids and derivatives has received 
much less attention than has been given to the previous series; partly 
because the differences between the parents are less striking and the 
diversity of segregation products was not so great. Two hybridizations 
were made: H,, which had calycina for the female and virginica for 
the male parent and H,, which was the reciprocal cross. 


1. PARENTS OF THE CALYCINA-VIRGINICA SERIES 


Elsewhere Setchell has given descriptions of calycina and virginica 
(‘‘Maryland’’). Like angustifolia and macrophylla, these two varie- 
ties possess distinet sets of characters which set them apart from the 
other Tabacum varieties that have been grown in the University of 
California Botanical Garden. 

Calycina is represented in our cultures by a variety, U. C. B. G. 
110/05, which was originally received from the Botanical Gardens of 
Cambridge University. The figure previously published (ef. Setchell, 
loc. citi pl. 4) well represents the general habit and type of the plant. 
The particular features of the characteristic teratological flower of 
yetter shown in plate 79, in which the leaf shape is also 
ore characteristic fashion. For illustrations of some 


calycina a 
illustrated in 
ich occur in the expression of the split hose-in-hose 
erred to Goodspeed and Clausen, 1917, plate 45. 
The legends to the two res of this plate should be reversed as indi- 
cated in the references to the plate in the text of this earlier article. 


of the variations 
flowers the reader is 


1922 | Setchell-Goodspeed-Clausen: Nicotiana Tabacum 495 


In stature, as previously mentioned, calycina belongs to the low 
corymbose group of Zabacum forms. In height the central axis usually 
varies between 60 and 75 em. The laterals, however, which develop 
later from the base, overtop the central axis and reach a height of 
120 to 185 em. Like macrophylla, central axis and laterals bear close 
panicles of corymbose racemes, the laterals developing successively 
from the base. The stems and branches are stouter than those of 
angustifolia and the leaves do not droop so considerably. In these 
respects calycina occupies an intermediate position between angusti- 
folia and macrophylla. 

The leaves of calycina, as plate 79 will show, are sessile, but they 
are distinetly different from those of either angustifolia or macro- 
phylla. Curiously enough, however, they do rather closely approxi- 


mate certain of the derivatives of the angustifolia-macrophylla series, 


as, for example, the LANCEOLATA and LORIFOLIA leaves of types 13 an 
14 respectively, illustrated in plates 75 and 76. The leaves vary from 
broadly to narrowly lanceolate, tapering toward both base ind apex, 
and usually with a long curved tip. The broader leaves he borne at 
the base of the plant, those above them becoming successively narrower 
in a continuous series until the linear leayes or ‘straplike bracts of the 
nflorescence a reached. There are no , at the base of the leaf. 
~The inflorescence is in the form of a very close panicle of racemes, 
the secondary axes of which are mostly patent, and more or less re- 
eurved or bent back. The flower as a whole is of a very characteristic 
spht hose-in-hose type. The corolla is usually split on one side, some- 
times twice split, and more or less eurved. The characteristic splt- 
ting of the corolla is seen even in very young buds and often the pistil 
protrudes from them. Typically the calyx has an elongated whitish 
green tube, with 3 to 5 of its tips more or less petaloid. Sometimes 
strips of petaloid tissue extend down the entire length of the calyx. 
The pod is ovoid oblong in shape. As it enlarges it splits the calyx, 
which then withers and drops off like the corolla, leaving a naked, 
whitish green capsule. The flower color is red fading to bluish purple, 
apparently the same as that of macrophylla. 

Virginica is represented by U. C. B. G. 78/05, a strai 
from the United States Department of Agriculture und 
fication number ‘‘205-20-7.’’ It is figured by Setch 
by Goodspeed and Clausen, plate 41, figure 1. Th 
flower characters are well represented in plate 8 


In stature virginica belongs to the moderate pyramidal group of 
Tabacum varieties. It is conspicuously taller than calycina, the cen- 


‘ 


496 University of California Publications in Botany [Vou. 5 


tral axis reaching a height of 150 to 175 em. While strong laterals 
develop they do not originate at the base of the plant as in calycina, 
and they do not overtop the central axis. These characteristics to- 
gether with the broad spreading basal leaves give the plant its pyra- 
midal or conical shape. The leaves are very close in general shape to 
those of calycina, but they taper less abruptly to either end. The apex 
is prolonged into a fairly long point curved to one side, and the base 
is expanded into two broad, partially clasping auricles. 

The inflorescence consists of a more ample panicle than that of 
calycina. The flowers are light pink in color, identical in this respect 
with those of angustifolia. The tube and infundibulum are narrow, 
gradually increasing in diameter from below in a funnel-shaped 
fashion. The corolla lobes are broad at the base, but have long, 
slender incurved points. Capsule and calyx present no very charac- 
teristic features, although the calyx is persistent in contrast to the 
deciduous ealyx of calycina. 

It will be seen from the foregoing decor that there are a 
number of distinct character contrasts between calycina and virginica, 
a brief note of which may well be made at this point. In flower color, 
red of calycina is contrasted with light pink of virginica, the same 
contrast which existed in the angustifolia-macrophylla series. Simi- 
larly the split hose-in-hose flower of calycina is contrasted with the 
normal one of virginica; low stature with tall; and a less decided 
contrast in leaf shape exists, depending upon the presence or absence 
of auricles at the base of the leaf. 


On F, OF THE CALYCINA—VIRGINICA SERIES 


In the season of 1910, 55 plants of 10F,H,, and 58 of 10F,H., were 
grown. In the season of 1911, 10 plants were grown of each of 
APH, andthe 

_ Like other hybrids which have been grown, these populations were 
uniform and equivalent throughout. It was thought that 10F,H., 
showéd a more distinctly pronounced trace of calycina characters than 
did 10% H,,, but the populations of the same seed grown in 1911 
showed ppreciable difference in this respect. 
appearance the F, plants resembled virginica more than 
The plants were somewhat shorter than virginica, 
em. In these plants it was noted that some of the 
laterals overtopped central axis as they do in calycina. The in- 
florescence was in general of the ample type characteristic of calycina. 


In gene 
they did calyc 
running up to 1 


1922 | Setchell-Goodspeed-Clausen: Nicotiana Pabacum 497 


The flower color was a deep pink intermediate between the two 
parents. The flower shape was normal throughout save that on every 
plant there was a small percentage of calyces with one or more pink 
and somewhat broadened ealyx tips, or with a streak of white on one 
side. Sometimes these partially petaloid calyces were partly decid- 
uous. In shape of flower the hybrid closely resembled virginica except 
that the corolla lobes were longer and more decidedly mucronate. 
Calyx and capsule were almost identical with those of virginica, the 
calyx being typically persistent and acerescent. The leaves were some- 
what broader proportionately than those of virginica, but they pos- 
sessed the pronounced auricles of that parent. The usual gradation 
in leaf shape on each plant from the broad basal leaves to the linear 
bracts of the inflorescence was in evidence. 

- The main features of H,, and H.,, are well illustrated in the draw- 
ings of 10F,H,,P, shown in plate 81. The general habit and charac- 
ters are illustrated in the photograph of 10F,H,,P.,, which is repro- 
dueed in plate 83, figure 1. ) 


3. F, OF THE CALYCINA-VIRGINICA SERIES 

In the season of 1911 four F, families of the calycina-virginica 
series were grown, viz., 11F,H,,P,,, 11F,H,.P,,, 11F,H.,P,, and 
iP). , 

As in the angustifolia-macrophylla series, the segregation exhibited 
in those four families, comprising 97 plants, was nothing short of be- 
wildering, and in most cases an intergrading series of forms connected 
one character expression with another. However, an attempt was 
made to classify the plants into categories suggested by the four pairs 
of character contrasts existing between the parents. The results of 
this classification are given in table 8. 


TABLE 8 
NUMERICAL DATA FROM F: POPULATIONS OF THE CALYCINA-VIRGINICA SERIES. 


Corolla color Corolla shape Stature Leaf width 
Bl lag) 4 : 
Garden Numbers 3 al & 2 |e | 6 5 
ele te | cel |) Eteach ge q 
11F.AisPo5 6 | 11 6 6 8 9 a 
11 F.Hy3P 49 7 | 14 4 | 12 4 9 11 
11 FHP; 5 9} 11 Ui 8 | 10 4 
11 FH Po¢ fy |) Alo) 8 | 10 6 a 8 
Totals 23) || 44 || 29) "35" 26) aso 67 | 30 


498 University of California Publications in Botany [ Vou. 5 


In this cross, corolla color behaved in exactly the same manner as 
it did in the angustifolia-macrophylla series. The same remarks as 
to sharpness of segregation apply here as in that series. Red was 
nearly always readily distinguishable, but pink and light pink formed 
a more or less completely intergrading series. Taking the results in 
this way, we obtain 23 red; 73 pink and light pink, which is substan- 
tially in accord with Mendelian expectations. 


TABLE 9 
F,; SEGREGATION IN CALYCINA-VIRGINICA SERIES. 
Pink Pink Red Red + 

Garden numbers normal hose-in-hose normal hose-in-hose 
16F2HisPo5 24 14 8 3 
16F2HisPa9 25 8 14 3 
16F2H.2P7 29 6 10 4 
16 F2H2P3s 30 8 11 1 

Totals 108 36 43 11 

Expected 112 37 37 12 


With respect to corolla form some difficulty was encountered be- 
cause the expression of the hose-in-hose character in the segregants 
did not seem to be so extreme as it was in the parent, and a large 
number of the plants showed slight traces of it, but sometimes in a 
more pronounced form than in the F, hybrids. Accordingly the elassi- 
fication of corolla form in table 8 is not a wholly satisfactory one. 

The classification for stature and leaf width is subject to similar 
remarks as to its definiteness. Here there was also a more or less 
completely intergrading series of forms and no accurate measurements 
were taken. However, there is no doubt that there was segregation 
with respect to these characters, and a range of forms was obtained 
which completely bridged the gap between the parents. The behavior 
of ‘these characters is to be considered in the light of their segregation 
sequent generations. 

16 four additional F., populations of the calycina-virginica 


series grown in order to reéxamine populations for the segrega- 


tion of nortial versus hose-in-hose flowers, and red versus pink flower 
10d of classifying the flowers was that used in studies 
of 1916 populations previously mentioned. The results of these studies 


are given in table 9. 


eolor. The m 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 499 


In the segregation the same grading as before of the pinks into 
two intergrading classes in the proportion of approximately 2 inter- 
mediate pink : 1 light pink was observed, but it was even more difficult 
to draw a line between light pink and intermediate pink because of 
the effect of the hose-in-hose conditon on flower color expression in 
those plants which bore teratological flowers. In the matter of segre- 
gation into normal and hose-in-hose flowers, some difficulty was ex- 
perienced because some otherwise normal flowering plants bore some 
flowers which showed a tendency for the calyx to become petaloid, 
and others bore flowers which showed a very slight hose-in-hose ten- 
dency. A correspondingly slight hose-in-hose tendency is also present 
in F, plants. These plants were classified as normal. Here again it 
can be seen that the segregation ratios of 144 pink : 54 red and 151 
normal : 47 hose-in-hose are in substantial agreement with Mendelan 
expectation for contrasts in a single pair of allelomorphs in each ease. 
Moreover, the dihybrid ratio is substantially in agreement with that 
expected for independent segregation of the members of these two pairs 
of allelomorphs. 


4, FB, AND SUBSEQUENT GENERATIONS OF THE CALYCINA-VIRGINICA 
SERIES 


In 1912 twelve F’, families of H,, and five of H,, were grown. They 
will be grouped for consideration according to the characters which 


TABLE 10 
F; BEHAVIOR OF RED SEGREGANTS. 
Garden numbers Red 
12F3HysP2sP 1 25 
12F3HisPo5Pi9 DNS) 
12F3HigP49Pi2 25 
12F3AygP49Po4 25 
12F 3H P 25 Pos 25 


the F, parent exhibited. In table 10 the data with respect t 
havior of F., populations from red flowering I, plants ar 
Five such populations gave nothing but red flowering pla 
clearly that red segregants breed true. In table 11 th 
flowering plants are similarly collected. The readér will not fail to 
notice that some pink flowering selections were not heterozygous for 


500 University of California Publications in Botany [ Vou. 5 


red. This bears out our statements as to the difficulty of classifying 
pink and light pink. In the seven populations which produced red 
flowering plants 38 plants had red flowers and 134 pink or pinkish 
flowers; again in substantial agreement with the behavior of flower 
color in the angustifolia-macrophylla series. The behavior of segre- 
gants classified as light pink is shown in table 12. Of the four popu- 
lations from which data were gathered only one bred true to light 


TABLE 11 
F3; BEHAVIOR OF PINK SEGREGANTS. 
Garden numbers Red Pink Light pink 
12F3Hj3P.;P7 5 16 4 
12F3Hy3P.;Po1 ea 21 4 
12F3HisP25Po5 6 19 : 
12F3HisP49P5 4 20 
12F His P4sPio 11 13 ae 
12F3HigP49Po5 4 16 5 
12F3H2PosPe5 4 20 
12F3H PoP 4 21 
Totals for segregat- 
ing populations 38 134 
TABLE 12 
F; BEHAVIOR OF LIGHT PINK SEGREGANTS. 
Garden numbers Red Pink Light pink 
12F 3 AisP2sPo4 FAs eee 23 
12F'3 HigP49P 20 8 12 5 
12F3HP7Ps 6 15 4 
12F 3H. P2sPs er | 25 


pink, one of the others bred true for pink, possibly a slightly darker 
shade than true light pink, and two segregated for all three colors; 
they must therefore have been pink heterozygotes. 

1 F, two populations each of H,, and of H,, were grown. Popu- 


lation#13F,H,.P,.P,,P, from an F, population breeding true for red 
gave i 100 plants all red flowering. Population 13F,H,,P.,P,,P,, 
from the Same F, population gave 97 plants all red flowering like 


uation 13F,H,,P.,P.P,, which bred true for pink in 
F,, gave in F, 96.plants, all pink flowering. These three populations 
were grown to F, without showing further evident segregation. The 


calycina. 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 501 


pink of the pink flowering derivative was at first considered somewhat 
darker in shade than the light pink of virginica, but this line also 
showed the hose-in-hose flower character, which sometimes makes it 
difficult to determine flower color accurately. In later generations of 
this line its color was noted as equivalent to the light pink of virginica. 


TABLE 13 
F; BEHAVIOR OF HOSE-IN-HOSE SEGREGANTS. 


Garden numbers Hose-in-hose 
12F3HisP25P.1 25 
*12F3H13Po5Po4 23 
12F3HisP49P5 24 
*12F3AigPa9Pi2 25 
12F3AysP19Po4 25 
12F;H2P26Ps 24 
1 2F 3H Pog P11 25 


* Apparently not so extreme as calycina. 


TABLE 14 
F; BEHAVIOR OF NORMAL SEGREGANTS. 

Garden numbers Hose-in-hose Partial Normal 
12F3HjgP2;P7 9 16 
12F3Hy3P25Pi1 4 4 17 
12F3HigP25Pis 5 20 
12F3HisP25P25 3 ae aD, 
*12F3HisPs9Pi0 Nee 4 20 
12F3HigP49P22 ass 25 
12F3HigP49 Pos a 21 
12F3H.P7Po 5 20 = 
12F 3 HPP; Ul 3 15 
12F 3H P26 Pos 10 15 
Totals 47 153 


Taking up corolla form next, we may deal with the different popu- 
lations in the same manner as was done in the ease of flower color. 
F, populations from F’, hose-in-hose segregants are recorded in table 
13. Seven populations were grown, all of which bred true to the 
hose-in-hose character, although curiously enough two pop 
Zhe b>, and 12h,H Pb did not appear to exh 
treme character expressions as calycina. 


Only one partially hose-in-hose plant was grown i a) Hor the 


sake of economy of space it is included in table 14, where it is marked 


502 University of California Publications in Botany [ VoL. 5 


with an asterisk. Strangely enough, it was one of the two in the table 
which did not throw hose-in-hose flowers. The other normal selections 
all threw hose-in-hose flowering plants in the proportion of about 3 
normal to 1 hose-in-hose. 

In subsequent generations only the three families which were pre- 
viously considered under flower color were grown. Normal flower | 
selections from 12F,H,,P.,P,, gave two populations, one of 100 and one 
of 97 plants. The plants all bore normal flowers. In 13F,H,,P..P,,P,, 
it was noted that some flowers were split, but there was not even a 
suggestion of approach to the true hose-in-hose condition. The other 
population 13F,H,,P.,P,;P, was from a hose-in-hose selection in the 


TABLE 15 
F; BEHAVIOR OF TALL SEGREGANTS. 


Garden numbers Tall Short 
12F3HisP25P7 19 6 
12F 3H y3Po5Po4 1 24 
12F3H_P7P5 6 19 

TABLE 16 


F; BEHAVIOR OF MEDIUM SEGREGANTS. 


Garden numbers Tall Short 
12F3HisP49P 12 2 23 
12F3HygPa9Po2 1 24 


corresponding F, population. Ninety-four plants were grown to ma- 
turity, all of which were strictly hose-in-hose. In subsequent gener- 
ations these three populations bred true to type save for the sporadic 
appearance of hose-in-hose flowers on plants which otherwise bore 
nothing but normal flowers. This, however, is not an unusual phe- 
nomenon even in pure line cultures of normal flowering varieties of 
Tabacum, and it is extremely doubtful whether the hybrid derivation 
of ‘these plants had anything to do with the production of occasional 
sph 


owers. 

espects height of plants the F, data are given in tables 15, 16, 
and 17, Which give the behavior of tall, medium, and short F,, segre- 
gants resp@etively. The behavior here is not very convincing. Prob- 
iffieulty in judging the character and the influence of 
variation in soil Gondition had something to do with it. 


1922 | Setchell-Goodspeed-Clausen: Nicotiana Tabacum 503 


In the subsequent generations the behavior was, however, more 
definite. 13F,H,,P.,P,,P, was grown from a tall F, plant. No defi- 
nite notes were taken as to height, but the population was noted as 
varying. In F. and subsequent generations the line bred true to tall. 
13F,H,,P.,P,,P,, was grown from a short F, plant. The ninety-seven 
plants were all of low stature and in subsequent generations the line 
bred true for low stature. 13F,H,,P.,P.P, was grown from a tall 
F, plant. Ninety-four plants, although variable in height, all be- 
longed in the tall class and in subsequent generations the line bred 
true for tall stature. Nothing but a careful biometrical study under 


TABLE 17 
F; BEHAVIOR OF SHORT SEGREGANTS. 

. Garden numbers Tall Short 
12F3HisPo5Pu 10 15 
12F3HisP25Pi9 16 9 
12F3Hy3P.;Po1 ri 25 
12F3HisP.; Pos 5 20 
12F3HigP19P9 iL 24 
12F3HigP49Pi0 339 24 

B's His P49 Pos 7 18 
12F 3 Aig Pap P25 ; 9 16 
IF’, op Pos Ps 8 16 
12F3H)PosPs 5 19 
12F3HopPo5Pi1 mee 25 
Totals 68 129 


well controlled cultural conditions, however, would yield results capa- 
ble of strict Mendelian analysis. However, it can be said that none 
of the results here recorded preclude the possibility of such an analysis, 
although it evidently can not be done in any simple qualitative manner. 

As respects leaf width it was found impossible to make even such 
a rough classification as was attempted in the case of stature. Here 
again nothing short of a strict biometrical analysis would furnish the 
basis for a Mendelian formulation. 


As has been indicated above, three separate lines of this series 
were carried out to the seventh hybrid generation. Of these 
a recombination of characters from both parents exhibitin& the tall 


504 ° University of California Publications in Botany [ Von. 5 


virgimca and the red flower color of calycina. The third had the tall 
stature of virginica and red flower color, in association with the hose- 
in-hose flower form of calycina. These three lines apparently bred | 
true for all their characters. 


5. DISCUSSION OF RESULTS OF THE CALYCINA-VIRGINICA SERIES 


No extended discussion of results is indicated in connection with 
the calycina-virginica series of hybrids because particular attention 
was given to so few characters. Just as in the case of angustifolia- 
macrophylla, so in this series of hybrids the character differences 
proved to depend upon complex genotypic differences. Apparently 
the flower color contrast in these two varieties was the same as that in 
the angustifolia-macrophylla series, and the same relations with respect 
to dominance and segregation were found to hold for it. Without 
doubt we are dealing here with the Rr pair of allelomorphs as in the 
previous instanee. The demonstration of the simple factor relations 
in the inheritance of the split hose-in-hose form of flower adds to our 
series another pair of allelomorphs which we may call Ce (calycine). 
In this case the dominance of normal over split hose-in-hose appears 
to be nearly, if not quite, complete. The sporadic appearance of split 
hose-in-hose flowers on otherwise normal plants does not even seem to 
be clearly associated with the heterozygous genotype, Cc. The data 
for height are not of sufficient accuracy or extent to warrant an at- 
tempt at Mendelian formulation. It was again found possible very 
easily to shuffle and recombine the characters occurring in the parent 
varieties and to establish recombination derivatives in pure lines. 


V. ALBA-MACROPHYLLA SERIES 
1. PARENTS OF THE ALBA~MACROPHYLLA SERIES 


Alba, which is one of the parents of the alba-macrophylla series, 
is the ‘‘White’’ tobacco, U. C. B. G. 30/06, described by Setchell. It 
is one of the taller forms of Tabacum, ranging in height from 165 to 
Typically alba is unbranched below; above, it has flowering 
branches forymbosely arranged in succession from above downward. 
The leaves are sessile, more ample, more rugose, and more velvety than 
those of mactophylla. They are narrowed suddenly above the ex- 
panded, somewhat auricled and partially clasping base. The leaves 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 505 


resemble those of macrophylla in shape but differ from them particu- 
larly in the basal portion. The corollas are white with a yellowish 
tinge ; but in shape, size, and general proportions they are very similar 
to those of macrophylla. Line drawings of typical: features of alba 
are reproduced in plate 82. The reproductions of photographs of the 
leaf of alba and of the F, hybrid of the alba-macrophylla series are 
shown in plate 84. 

Macrophylla, U. C. B. G. 22/07, has been deseribed above. 

In these two varieties there are definite character contrasts in color 
of flowers, macrophylla being red and alba white; and in stature, 
macrophylla being low of stature and alba distinetly taller. Other 
contrasts also exist, although they are not so definite, in the style of 
branching and in the shape and texture of the leaves. Like those 
which have been considered above, this is a hybrid series in which 
the contrasts between the parent forms are of a distinctly complex 
character. 


2. F, OF THE ALBA-MACROPHYLLA SERIES 


The crosses between alba and macropyhlla were made in July, 1909. 
The cross was successful in both directions, and seed was secured from 
albaQ x macrophyllag, which was given the number H,,, and from the 
reciprocal which was given the number H.,,. 

When mature the F, plants were tall, 100 to 200 em., averaging 130 
to 160 em. Habit and leaf shape were in general those of alba. The 
corolla was deep pink of about the same shade as that of the F, of 
the angustifolia-macrophylla series. The variation in height in these 
populations possibly indicates a lack of constaney in the alba parent 
in this respect. In plate 83, figure 2, is shown an F, plant of 10F,H.,. 


3. F, OF THE ALBA-~-MACROPHYLLA SERIES 


In 1911 four F,, populations were grown, viz., 25 plants each of 
EES ey Pie eerand ll HH and) 23 plantsronellkkysklenby. ». 
The four populations, although small, proved to be equivalent in every 
respect. The type of segregation was very complex. That of differ- 
ences in types of leaves, especially, presented such a series of inter- 
gradations as to defy any definite classification. Likewise in héight, 


there was a continuous series of forms from the tallest to the 
‘A rough classification was, however, made for purposes ofsreference 
the segre- 
hich shows 


into tall, medium, and short. An excellent illustration 
gation for this character is shown in plate 85, figure 1, 


506 Umversity of Califorma Publications in Botany [ Vou. 5 


two adjacent plants of 11F,H,,P.,, one tall and of the general habit 
of alba, and the other short and of the general habit of macrophylla. 
The classification for height is given in table 18. Obviously no satis- 
factory Mendelian formulation can be deduced from these data. 

As regards flower color, however, the classification is more definite. 
Four more or less distinct shades were distinguishable, viz., red, pink, 
light pink, and white. The pink and light pink shades merged into 
each other, consequently they have not been separately recorded in 
table 18. Bearing in mind the previous behavior of red and pink, as 
shown in the angustifolia-macrophylla and calycina-virgimea series, 


TABLE 18 
F, SEGREGATION IN THE ALBA-MACROPHYLLA SERIES. 
Stature Flower Color 
Garden numbers 
tall medium short red pink white 
11FHo3Pi3 101 6 8 3 14 8 
11 F.Ho3P31 13 6 6 4 12 9 
11 F,Ho4Pe a 10 8 3 15 7 
11 F,HsP34 6 8 9 6 13 3 
Totals 37 39 31 16 54 27 


it would appear that we are here dealing with dihybrid populations 
in which a pair of allelomorphs for color versus white is concerned in 
addition to that pair upon which the contrast of pink versus red was 
found to depend. The pair of allelomorphs for the pink versus red 
contrast has been represented by R and r, respectively. If we repre- 
sent the contrast of color versus white by W and w, respectively, the 
two parents in this series would possess the following genotypes: 


Alba — RRww 
Macrophylla = rrwWw 


The light pinks of the previous series would then be RRWW, and the 
factor R might be regarded as a dominant diluter. According to this 
ulation, F', of the alba-macrophylla series would be RrWw, pink, 
» Should segregate in the ratio 3 red : 9 pink : 4 white. The 
result in the classification of ninety-seven plants in whole 
numbers is 18 red : 55 pink : 24 white. Agreement is thus fairly close. 

A check,on the results above noted for the 1911 sowings of the F, 
as made by growing in 1916, five additional F, popula- 


population 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 507 
tionseet the sameseries, yaz., 16E..P,: 16FH,.P.,;: 16F,H,,P,,; 
16F,H,,P.,; and 16F,H,,P,,. The segregation in the resulting popu- 
lations is recorded in table 19. 

The method of studying these flowers was the more accurate one 
previously described in connection with later generations of the 
angustifolia-macrophylla series. In the classification of flowers it was 
noted: that reds and whites were sharply distinguishable from pinks. 
The pinks were of many different shades; some very light, others rela- 
tively dark, corresponding to the range obtained in the angustifolia- 
macrophylla series. However, in these populations the range of vari- 


TABLE 19 
F, SEGREGATION IN 1916 SOWINGS OF ALBA-MACROPHYLLA SERIES. 
Garden numbers Red Pink White Totals 

16F.H»;P; 11 18 11 40 
16F.H»3P 3. 12 19 11 42 
16 F 2H»; P34 8 24 9 41 
16F>H.4Po3 5 34 11 50 
16F.H4P33 0h 29 14 50 
Observed 43 124 56 223 
Expected 42 125 56 223 


ation of pink appeared to be greater and the intergradations more 
gradual than in that series. In the whites there was also evidence of 
differentiation into classes depending upon the amount of yellow or 
creaminess in the flowers. Some of the whites appeared to belong to 
a clear white albino class, but most of them had a distinetly creamy 
tinge. The observed segregation in these populations was in almost 
exact agreement with the formulation advanced above. 


4. F, AND SUBSEQUENT GENERATIONS OF THE ALBA-MACROPHYLLA 
SERIES 


In table 20 we have summarized the behavior of the F,, populations 
as respects color of flowers and height of plant. Of the five red/F, 
plants from which F,, populations were grown, three proved be 
homozygous for red and one proved to be a heterozygote of the*genetic 
constitution rrWw. Of this latter selection two sowings wére made, 
one in 1912 and another in 1913. The combined results.from these 
two sowings, 35 red: 14 white, are in fair agreement with Mendelian 


508 University of California Publications in Botany | VoL. 5 
expectation. The other population exhibited an anomalous type of 
segregation, and gave 2 red :23 white. It is unfortunate that this 
line was not investigated further, but the results probably are due to 
an experimental error. 


TABLE 20 
F; SOWINGS OF THE ALBA-MACROPHYLLA SERIES. 
F2 Phenotypes Flower Color Stature 
Garden —EE es 
Flower Numbers tall (or 
Color Stature Red pink white short medium) 
Tall (or M) 12F3H»3Pi3P3 19 sone 6 25 
Short 12F3H23P31P1 22 ie Sse 22 boo 
Red Sh’t (orM), 12F3Ho3P31 P17 25 Bhan shee 4 PAL 
Tall 12F3H»3P31P 52 24 Ase 60 4 20 
Tall 12F3;H23P31P.5 2 Se 23 1 24 
Tall 16F3;H.3PisP; |. 16 set 8 
Tall 12F 3H»; PisP1; 2 14 6 8 10 
Medium 12F3H.3P13P25 6 12 a 22 =e 
Tall 12F3H»3P31P7 6 14 i) 25 
Tall 12F3H»3P31Pi9 10 9 4 ace 23 
Pink | Medium 12F3H23P31P20 6 12 5 » 4 19 
Tall 12F3;HPsP; 3 22 a ihe 25 
Short 12F;HyPssPis 5 13 7 24: i. 
Tall 12F3H.4P34P20 ro 20 5 en 25 
Tall 16F'3Ho4P34P 9 aire 13 4 
Tall 12F3Ho3PisPi4 oe wigs 25 a 25 
Tall 12F3Ho3Pi3Pi5 ape bee 25 ne 25 
Short 12F 3 H.3PisPo4 — mn 25 25 ee 
White Tall 12F3H4PsP2 arenas S260 24 Sette 24 
Short 12F3Ho4P.6P3 Rite oe 25 4 21 
Tall 12F3;HoyP5Ps 3 ae 23 = 23 
Short 12F3HosP34Po3 Ah 1 23 25 
Short 13F3Ho3Pi3P 54 5000 ee 10 10 
Short 13F3Ho4P34Po3 fe Ree 10 10 


Eight families of F., plants were grown from pink F,,’s. Of these 
I, plants six proved to belong to the RrWw genotype. The totals 
from these six populations, viz., 35 red : 74 pink : 34 white, are in fair 
agreement with the dihybrid ratio 3 red :9 pink :4 white. One of 
the other populations gave 3 red : 22 pink. It was probably the result 
ing seed from an F, plant of the genetic constitution RrWW 
uld give 3 pink :1 red. The observed segregation ratio is 
not good, but the numbers are small. Two sowings of F,H,,P.,P., 
gave tot f 33 pink :9 white. The F, plants in this case must have 
been of the genetic constitution RRWw; in which case expectation 
would be 3 pink :1 white. No selection was observed to breed true 


which 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 509 


for pink in F,. This, however, is not inexplicable, for only one in 
nine among the F’, pinks should belong to the RRWW genotype. 

Sowings were made from seven white F’, plants. Among 190 plants 
so produced there was one pink flowering individual. It surely rep- 
resents some kind of experimental error. We may say, therefore, that 
for flower color the formulation advanced to account for the F, segre- 
gation ratio, also accounts for the behavior observed in the various F, 
populations. 

We have reported the data on height in table 20, largely in order 
to show that this character, although obviously dependent on factor 
differences, is so complex as not to permit of a simple qualitative 
treatment. Thirteen F, sowings from tall F, plants gave ten popu- 
lations showing only tall plants. Two of the remaining populations 
showed segregation into 31 tall (and medium) : 13 short. One popu- 
lation consisted entirely of short plants. The classification of the F, 
parent of this plant as ‘‘tall’’ was noted as doubtful at the time, the 
note ‘‘or medium’’ being appended. Two-populations were grown 
from F’, plants of medium height. One of these populations was uni- 
formly of low stature; the other showed segregation into 19 tall (and 
medium) :4 short. Six populations were grown from F,, parents, 
four of which apparently bred true for low stature, the other two 
showed segregation into tall (and medium) or short in the ratio 42 : 8. 
It is interesting to note that at the time of classification the parents 
of these two later populations were classified as short (or medium), 
indicating a doubt as to proper classification. More definite data will 
be necessary before a satisfactory formulation of these height differ- 
ences can be made, but certain of our results seem to indicate that 
there is one allelomorphie pair which has a rather marked effect on 
stature, and that there are other subsidiary pairs of factors which 
have less marked effects. 

Only one line in this alba-macrophylla series was carried out to 
subsequent generations to demonstrate the possibility of fixing char- 
acter complexes from a hybrid. It was a low stature white flowering 
line. In F,, 100 plants of 13F,H,,P,,P,,P. bred true to low stature 
and white flower color. The population was uniform, the plants ex- 
hibited the general habit of macrophylla rather than that of alba; and 
the leaves were the same shape as those of macrophylla, but they were 
slightly rugose, although not so much so as those of alba. In [F'., two 
populations of 25 plants each were grown, viz., 14F,H.,P4P...P.P,, 
and 14F.H,,P,,P.,P.P,,. No differences were detectable between these 
two populations, and the characters exhibited were those we have noted 


U, OF ILL, LIS. 


510 University of California Publications in Botany [ Vou. 5 


for F,. In F, 10 plants each of 15F,H,,P,,P,,P,P.,P, amd 15¥',H., 
P,,P.35P,PssPa2 aud in F’, 10 plants each of 16K. H.,P. eae ee. 
and 16F,H,,P,,P,,P,.P,,P,;P, were grown. In both cases the parallel 
populations were equivalent and the characters exhibited and described 
in F, remained constant. Plate 85, figure 2, is a good illustration of 
the type of this family as fixed. A photograph of the original F, 
plant, from which the family descended, is reproduced in plate 85, 
figure 1. It will be noted that the derivative represents a fixation of 
the characters of the original F, selection, and that no important seg- 
regation occurred in it either in F, or in subsequent generations. 


5. DISCUSSION OF RESULTS OF THE ALBA-MACROPHYLLA SERIES 


Here again, as in the calycina-virginica series, no extended discus- 
sion of results is necessary. Obviously the differences separating the 
two varieties are of a complex nature genetically as in the two previous 
eases. The series demonstrates the existence of another pair of allelo- 
morphs for flower color in this group of 7abacum varieties, viz., Ww, 
and the part played by it in the production of both red and light pink 
flower color has been determined. The height contrast again proves 
to be too complex for qualitative Mendelian formulation. As in the 
previous eases, the establishment of stable recombination derivatives 
proved to be a simple task. 


VI. GENERAL CONCLUSIONS 


We shall limit the discussion of these results to three main topies 
upon which these investigations seem to have thrown some light: (1) 
the origin and interrelationships of varieties of Tabacum; (2) the 
methodology of Mendelian analysis in Tabacum; and (3) Mendelian 
heredity in Tabacum. 


1, ORIGIN AND INTERRELATIONSHIPS OF VARIETIES OF TABACUM 


As a result of extensive studies of a considerable assemblage of 
Tabacum varieties, Comes (1905) came to the conclusion that the 
species Tabacum could be subdivided into six fundamental varieties: 

a. var. fructicosa Hook. 
b. var. lancifolia (W.) Comes. 
>. var. virgimca (Agdh.) Comes. 
var. brasiliensis Comes. 
e r. havanensts (Lag.) Comes. 
ife var. macrophylla Shrank. 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 511 


Inasmuch as practically every Tabacum variety shows combinations 
of characters of two or more of these fundamental varieties, Comes 
assumed them to have been derived mostly through hybridization be- 
tween the fundamental varieties, and he proceeded from purely morph- 
ological studies to classify the different commercial varieties on the 
basis of their supposed hybrid derivation. Anastasia (1906), who 
has criticized this scheme of Comes very severely, reduced the number 
of fundamental varieties to four, striking out fructicosa and lanctfolia 
from Comes’ list, and substituting purpurea for macrophylla.  Al- 
though disagreeing as to the fundamental varieties, Comes and Ana- 
stasia seem to agree in referring existing varieties to derivation, mostly 
through hybridization, from a relatively small number of fundamental 
varieties. 

The Howards (1912) object to the mode of classification of Comes 
and Anastasia, and point out as a result of their studies of types of 
Indian tobaccos that no attempt at classification based on derivation 
can be considered seriously unless supported by actual experimental 
studies. In her later paper in particular Miss Howard (1913) shows 
that segregation products may be obtained through hybridization 
which transcend the limits set by the parents. The Howards propose 
a scheme of classification based primarily upon leaf and habit char- 
acters, and they adopted this morphological system purely as a pro- 
visional means for facilitating identification and reference among the 
numerous forms of Indian tobaccos. 

Our results agree with those stated by the Howards, and we raise 
the same objection to schemes of classification such as Comes and 
Anastasia have advocated. Any scheme of classification based on 
morphological considerations alone cannot well meet with the approval 
of geneticists, for it does not take into account genotypic differences 
which exist among forms of similar morphological appearance. Thus 
it is possible, as Miss Howard points out, by crossing different mem- 
bers of a given group to obtain segregation products which belong in 
an entirely different morphological group in the scheme of classifica- 
tion. In particular she points out that ‘‘petiolate’’ forms have been 
produced as segregation products from two ‘‘sessile’’ parents, yet 
‘‘netiolate’’ and ‘‘sessile’’ have been used as primary indexes for 
classification of tobaccos into groups. : 

The difficulty from the genetic point of view with any Classieiienien 
of Tabacum varieties is the same as that which is met with in the 
classification of varieties of other polymorphic species. ing the 
species as a whole and viewing the entire assemblage of its varieties, 


512 University of California Publications in Botany [ Vou. 5 


there is evidently in Tabacum, to those who accept current interpre- 
tations of heredity, a series of allelomorphie contrasts, the number of 
which cannot even be guessed, but which need not perhaps be more nu- 
merous or striking than those which have been discovered in Drosophila. 
But whereas in Drosophila the factors have been kept in stocks in- 
volving for the most part single factor differences from a common wild 
type, in Tabacum, and in other cultivated crop plants such as barley, 
maize, oats, rice, wheat, ete., these factor differences have been shuftled 
about through long periods of cultivation until existing varieties are 
no longer related clearly to a common form or to each other. In some 
instances in such groups certain factor differences have a more strik- 
ing visible effect than in others. In such instances we have an obvious 
mode of classification based not upon number of factor differences so 
much as upon the striking character differences which arise from 
certain factor contrasts. Thus in barley we have the classification of 
varieties advocated by Harlan (1918) based upon recognition of a 
number of major morphological distinctions, some of which at least 
have been clearly analyzed in Mendelian fashion; and the same prin- 
ciple has been recognized in the classification of varieties of maize, 
where it has led to the absurdity of erection of a heterozygous form, 
podded maize (vide Collins), as one of the primary group distinctions. 
In some instances, doubtless, the sorting of factors may give rise to 
certain recombinations which are more favorable to life processes than 
others, as Muller has pointed out in another connection, and such 
genotypes may act as centers around which groups of varieties may 
be built up, thus giving rise to more or less obvious grouping of varie- 
ties. The attempt to base a system of classification upon reference to 
certain fundamental types does not, however, promise much simplhi- 
fication of the difficulty; moreover, such an attempt rests upon the 
rather naive assumption that it is unnecessary to account for the 
fundamental types. 

From a genetic standpoint, therefore, it would appear that in 
attacking the problem of classification and interrelations of varieties 
in a polymorphic species the major premise should be a recognition 
of the fundamental equivalence of every homozygous genotype. Start- 
ing from this premise a system of dichotomy beginning with those 
faetor contrasts which produce the most striking, visible effects and 
procéeding to those of lesser effect might be set in operation. Such a 
system. obviously would in certain cases separate some similar varie- 
ties intO\separate groups, and would lead to recognition of group 
differences*without obvious morphological distinctions, but the system 


1922) Setchell-Goodspeed-Clausen: Nicotiana Tabacum 513 


would have a real significance, and the relationships indicated by it 
would be fundamental ones. It is, however, necessary to have a much 
more extensive knowledge of Mendelian heredity in Tabacum than we 
have at present before such a system can be formulated. 


2. METHODOLOGY OF MENDELIAN ANALYSIS IN TABACUM 


From the Mendelian side there are certain obvious facts associated 
with Tabacum as a species. In the first place, as we have stated before, 
the species is highly polymorphic. A large and striking assemblage 
of varieties exists, the most extreme of which hybridize readily and 
give fully fertile hybrids and full fertility in their derivatives. A 
few teratological forms are known in which fertility is somewhat re- 
duced, but the above generalization does not far overstate the facts. 
The species is, moreover, so highly polymorphic that with respect to 
any given character a representative collection of varieties may be 
arranged in a series connecting the most extreme expressions of that 
character by imperceptible steps. Thus in flower color we have repre- 
sented in the collection of varieties of the University of California 
Botanical Garden dark red, red, light pink, pinkish, and white, and 
descriptions occur in the literature which indicate the existence of 
further shades of red connecting these. Now flower color is a rather 
definite character, comparatively speaking, for it appears to be little 
affected by ordinary environmental conditions. In many polymorphic 
forms, such for example as maize, there are a large number of such 
definite characters, and as a consequence studies of inheritance in 
these forms have resulted in definite Mendelian analysis of many char- 
acter differences. But in Tabacum unfortunately most of the char- 
acters involve quantitative elements, and these with few exceptions 
depend so largely for their particular expression upon environmental 
conditions that it becomes a difficult matter in a segregating population 
to distinguish between those differences which are inherent and refer- 
able to the genotype and those which have come about through the 
action of extrinsic forces. And yet our assemblage of tobacco varie- 
ties indicates clearly that there are genotypes which give rise to all 
possible expressions in these characters. Here we find the reason for 
the present backward state of knowledge of inheritance in Tabacum, 
for while there have been numerous investigations which indieate 
clearly that the Mendelian mode of transmission may be followed in 
all these character differences, yet there are very few a 
which have resulted in the precise type of factor analysis characteristic 


514 Unversity of California Publications in Botany [Von. 5 
of investigations with other forms, specific mention of which is un- 
necessary. 

The general features of inheritance in Tabacum varietal crosses 
are plain enough. The results of our investigations in this connection 
agree throughout with the conclusions which Miss Howard drew from 
her studies. When we are dealing with complex differences, the F, 
is commonly intermediate in character expression between the two 
parents. Not only is this true as respects the F, plant as a whole but 
it is also true for individual characters. The F,, commonly consists 
of a varied assemblage of forms covering the range between the two 
parents, or even not uncommonly presenting products not ineluded 
in the range between the two parents. So many and of such variety 
are the forms obtained that accurate classification is entirely out of 
the question. But in F, and in subsequent generations segregation, 
even for characters commonly regarded as quantitative, sometimes 
occurs in distinet discontinuous classes in marked contrast to the inter- 
grading series of forms obtained in F,. This is shown particularly 
well in our analysis of leaf base factors, for in this case we have been 
able to adopt a qualitative mode of attack on one of the features which 
contributes to leaf shape. If such an analysis proves successful in 
one instance, there seems to be little reason why it should not be ex- 
tended to others. There is, therefore, additional evidence in this suc- 
cessful application of the mode of qualitative analysis to quantitative 
characters in support of the oft repeated contentions of East (1913), 
Hayes (1912), Hayes, East, and Beinhart (1913), Miss Howard 
(1913), and others that fundamentally the same mode of inheritance 
holds for quantitative characters in tobacco as for qualitative ones. 
The distinction between the two classes of characters is purely an 
artificial one erected for the purpose of convenience in formal treat- 
ment, and at most depending merely upon an increase in complexity 
of the factor relations involved and on the greater fluctuation of the 
characters in response to environmental differences. 

The question remains to be discussed whether semiquantitative 
characters admit of a qualitative mode of analysis, and if so, how? 
Miss Howard (1913) as a result of her extensive studies of inheritance 
in Indian tobaccos concludes that the easiest way to determine the 
principles underlying inheritance in these forms is to establish as 
many extracted homozygous intermediate forms as possible. The estab- 
lishment of such forms in themselves, however, is only a step in the 
Mendelian analysis of the differences. Such forms are, as might have 
been expected on theoretical grounds alone, less different from one 


1922] Setchell-Goodspeed-Clausen: Nicotiana Tabacum 515 


another and from the parents than the original parents are from each 
other. Moreover, our experiments show that as a result of simplifi- 
eation of the factor differences the derivative strains crossed with each 
other or with the parents give F,, progenies which often exhibit clear- 
cut segregation in characters which showed intergrading series in the 
original F, population. In other populations, however, from crosses 
between derivatives, the populations still exhibit perplexing com- 
plexities which make classification difficult and uncertain. In such 
cases we could again resort to the method of establishing intermediate 
derivatives from them; but if the number of factors concerned in a 
given character is even moderately large, as is certainly the case with 
many of these quantitative characters, the number of genotypically 
different derivatives which may be secured becomes so great as to make 
the method impracticable. 

Our experience indicates that the successful factor analysis of these 
quantitative character differences depends not only upon getting what 
Castle (1919) has called the residual heredity equivalent throughout 
the population, but also in establishing the proper kind of residuum 
which will most emphasize the character differences associated with 
the pair of factors or pairs of factors under investigation. The prob- 
lem may be illustrated crudely by considering the pair of flower color 
factors Rr. If the residuum should contain PP, the effect of which 
is described below, segregation would give PPRR, PPRr, and PPrr. 
In character expressions these three different genotypes would doubt- 
less all be of various shades of dark red, difficult or impossible of ac- 
curate separation. With such a residuum, therefore, it would be im- 
possible to investigate satisfactorily inheritance in the factor pair Rr. 
But if we should substitute pp for PP in the residuum, the segregation 
products would be ppRR and ppRr, which would be pink, and pprr, 
which would be red. Here the segregation would be sharp and dis- 
tinet, and there would be practically no difficulty in classification. 
How complex such interrelations can be has been shown most clearly 
by Bridges (1919) in his account of specific modifiers of eosin in 
Drosophila. As Bridges shows it would easily be possible to obtain 
populations of Drosophila defying classification, but by keeping the 
factors separate and studying their character effects with known 
residual genotypes, it has been possible to determine and locate the 
factors involved. Doubtless much of the extraordinary success of 
Mendelian analysis in Drosophila has been due to the fact that factor 
differences arose under conditions such that the residual otype 
gave no difficulty ; whereas in crop plants, the geneticist starts with 


516 University of California Publications in Botany [ VoL. 5 


long established diverse types, evidently related to one another in 
fundamentally the same manner as are the various Drosophila mutants, 
but more complexly, and from these complex assemblages he must 
unravel the tangled skein of heredity. 

There are, however, other and perhaps quicker ways of establishing 
a uniform and favorable residual heredity than that of securing and 
testing homozygous extractives, and these may be employed in certain 
special cases. Thus, if it be desired to study the relationship of the 
pair of factors Ss for the petioled versus sessile condition, it should 
be possible to proceed by crossing back the F, of angustifolia x macro- 
phylla, for example, to macrophylla, selecting the petioled forms from 
the back cross for again crossing back to macrophylla, and continuing 
the process until clear-cut segregation was obtained. Such a mode 
of procedure should establish a residual genotype equivalent to that 
of macrophylla itself, and should thereby enable the student event- 
ually to.study the effect of substituting SS for ss in the macrophylla 
genotype. In tobaccos technical details make it particularly easy to 
adopt such a procedure, but it is useless to speculate further upon its 
results until it shall have been attempted. 


3. MENDELIAN HEREDITY IN TABACUM 


From the standpoint of factor analysis, we have demonstrated 
clearly in the foregoing pages, the existence of a number of distinct 
pairs of factors. Two of these affect flower color, one flower form, 
and three affect the character of the leaf base. The particular effects 
of the opposing members of these pairs of factors and the interrela- 
tions which they exhibit so far as these have been investigated have 
been set forth in the discussions which follow the deseription of each 
of the three series of hybrids. Although evidently many other factor 
differences were concerned in these studies, and remain for further 
investigation, the results which we have described make a beginning 
toward a more accurate knowledge of Mendelian heredity in Tabacum. 

So far as our results furnish any data on the question, the six ~ 
pairs of factors isolated exhibit no linkage relations. The data here 
are far from complete, but the results are in accordance with theory. 
According to White (1912), there are twenty-four pairs of chromo- 
somes in Nicotiana. Assuming for the sake of discussion that each 
of x pairs of chromosomes bears a set of factors comparable in 

bérs to any other pair, then the chances of finding linkage when 
.. of factors are studied is very slight. This large number 


num 
only six 


1922 | Setchell-Goodspeed-Clausen: Nicotiana Tabacum D17 


of pairs of chromosomes may account for the ease with which recom- 
bination pure lines were established. Even with a large number of 
factor differences, such as evidently distinguish these Tabacum varie- 
ties, the chances are slight with so many pairs of chromosomes that 
linkage will enter in as a factor to cause the continued preservation 
of a heterozygous condition as a consequence of selection for a certain 
set of characters. 

It remains to consider those portions of the Nicotiana literature 
which deal specifically with the Mendelian inheritance of the charac- 
ters which we have investigated, and to harmonize our results with 
those which have been reported previously. Unfortunately there have 
not been many investigations in Tabacwm which have been prosecuted 
far enough to arrive at a definite factor analysis of the differences 
under consideration. The investigations of Miss Howard (1913), 
promise of the continuation of which has not thus far been fulfilled, 
in general confirm those which we have presented in this paper. On 
the strictly analytic side, however, Miss Howard did not carry her 
work very far. This doubtless was due to the difficulty of making a 
factor analysis of the characters which she selected for study, viz., 
(1) time of flowering, (2) height of stem, (3) arrangement of the 
leaves on the stem, (4) length of the decurrent portion of the lamina, 
(5) venation of the leaf, (6) leaf shape, and (7) undulation of the 
surface and margin of the leaf. For most of these characters she 
demonstrates, by the presentation of numerical data in some cases 
as far as F,, the probability of the character differences in ques- 
tion depending upon multiple factor differences. In the case of height 
certain of her cultures strongly suggest the existence of a pair of 
allelomorphs, which has a relatively great effect, for in some of her 
cultures there are definite discontinuous height differences. For the 
inheritance of length of the decurrent portion of the lamina Miss 
Howard postulates the existence of at least three or four distinet pairs 
of factors. As respects leaf base, she records the synthesis of petiolate 
types from sessile parents, observing in two cases a simple 1:2:1 segre- 
gation into petiolate : intermediate : sessile. As respects corolla color, 
she records one F’, population from pink x very pale pink fading into 
white which consisted of 72 pinks of various shades to 45 whites, but 
some of the palest pinks were indistinguishable from white. She found 
evidence of grouping among the pinks, and postulates the existence 
of two factor differences to account for it. The investigations which 
we have reported do not throw light upon the factor constitution of 
the very pale pink varieties with which Miss Howard worked. Our 


518 University of Califorma Publications in Botany [ VoL. 5 


varieties angustifolia and virginica have lively pink flowers. Of the 
paler pinks or ‘‘pinkish’’ forms we have a representative in our N. 
Tabacum var. Cavala, U. C. B. G. 72/05, which has flowers distinctly 
lighter in color than those of angustifolia or virginica. Our petiolate 
forms also seem to be of different constitution from those with which 
Miss Howard worked, for she presents evidence to show that hers are 
combinations of recessive factors and that they breed true whenever 
they occur as segregation products, whereas our petiolate forms often 
gave plants with sessile leaves as segregation products. We have, 
however, secured evidence that some distinctly short petiolate forms 
arise from sessile ones, perhaps by modifications of the AURICULATA 
leaf type in the direction of stripping the auricle and lower portion 
of the lamina from such leaves, but our results are not yet definite 
enough to permit of rigid formulation. Further investigation of the 
relationships of the various petiolate forms is necessary. 

As respects flower color Allard (1919) has presented some inter- 
esting data which at first sight appear to contradict those which we 
have presented. Allard found that carmine x pink gave F, carmine and 
F, 3 carmine :1 pink. The back crosses gave consistent data. Thus 
F, carmine x carmine parent gave all carmine, and F, carmine x pink 
parent gave 1 carmine :1 pink. In F, pink segregants bred true for 
pink, and carmine either bred true for earmine or gave again 3 carmine 
:1 pink. The difficulty here is that our red is not genetically identical 
with Allard’s carmine. Our flowers of macrophylla and calycina at 
full expansion show a color lying between rose red and pomegranate 
purple of the Ridgway color scale. This color, which we have called 
red for the sake of brevity, is very close to carmine, but we have an- 
other flower color, which we eall dark red, represented by N. Tabacum 
var. macrophylla purpurea, which is probably identical with the Giant 
Red flowering tobacco which Allard used in his experiments. 

We have made some preliminary tests of this dark red, and find 
that it behaves differently from red. Crossed with our white it gives 
dark red in F,, instead of pink as was obtained from red x white. 
Since our white carries the factor R, which is responsible for the 
production of pink flower color, dark red must differ from pink in a 
dominant factor. If we call this factor pair Pp, then our various 
colors of tobacco would have the following genotypes: 


Darkgredse—. 5 eee WWRRPP 
Red. 320. a WWrrpp 
\ Pink? A022 er WWRRpp 


1922 | Setchell-Goodspeed-Clausen: Nicotiana Tabacum 519 


Obviously this formulation would account for Allard’s results with- 
out contradicting those which we have presented, but inasmuch as our 
experimental evidence is not yet complete we refrain from any further 
discussion of the consequences of this scheme save one. Allard presents 
certain data for a cross of carmine x white which gave in F, light 
earmine, and in F’, 3 colored : 1 white, the colored being various shades 
of carmine and pink. Allard’s discussion of this case is somewhat 
mixed, but he evidently erroneously expected a simple monohybrid 
segregation of the 1 :2:1 kind. That more than one factor is con- 
cerned in the cross is clearly shown by the results of crossing some of 
the extracted whites with pink varieties. The results of three such 
crosses gave: 


1. Pink (Maryland Mammoth) x Extracted white.................. 36 carmine : 18 pink 
2. Extracted white x Pink (Maryland Mammoth)................ 20 carmine : 23 pink 
3. Pink (Conn. Broadleaf) x Extracted white.......................- 12 carmine : 39 pink 

TN Ojb Se ese. sot ssccss2 scaccestessescccoscencnacce ose aueneee Ses laeanees 68 carmine : 70 pink 


In (1) above we have combined in the carmine class 17 carmine and 
19 somewhat lighter than carmine. 

If we consider a cross of dark red x white according to the genetic 
formulation given above, the F, should be dark red, and F, should 
consist of 9 dark red : 3 pink :4 white. Doubtless the pinks and the 
dark reds would exhibit various shades, but the three classes should 
be distinct. If we combine ‘‘carmine’’ and ‘‘lighter than carmine’’ 
to form a carmine class and dark and light pink to form a pink class, 
Allard’s F,, data reduce to the following form: 

149 carmine : 64 pink : 65 white. 
This ratio compares very favorably with a 9 :3 :4 expectation, viz.: 
157 dark red : 52 pink : 69 white. 
No F, results from sowings from colored F, plants are given, but the 
single F, white, which gave when crossed with pink approximately 
equal numbers of carmine and pink flowering plants, is accountable 
for as of the genotype wwRRPp. Further investigations are in pro- 
gress for the purpose of determining precisely the relation of dark 
red and pinkish to the red, light pink, and white colors reported upon 
in this paper. 

There are other references in the literature to Mendelian inherit- 
ance in Tabacum, but inasmuch as these do not bear upon othe 
characters which we have attempted to analyze it does not ee 
necessary to discuss them at this point. 


520 Unversity of Califorma Publications in Botany [ Vou. 5 


VII. SUMMARY 


Studies of three intervarietal crosses in Tabacum demonstrate that : 

1. All the differences between varieties of Tabacum can be analyzed 
in a Mendelian fashion, if sufficient refinement in methods be intro- 
dueed. 

2. Stable recombinations of parental characters can readily be 
obtained with three or four generations of self-fertilization. 

3. Characters outside the range between the parents are sometimes 
produced following hybridization, and these may be readily established 
in stable lines by self-fertilization. 

4. The petioled leaf base of angustifolia and the sessile leaf base 
of macrophylla differ in at least three pairs of factors. 

5. A single factor difference exists between normal and spht hose- 
in-hose flowers. 

6. Two pairs of factors account for the relation existing between 
red, light pink, and white flower color. <A third pair of factors is 
necessary to account for dark red. 

On the theoretical side it has been pointed out that: 

1. Derivation of relationships and erection of systems of classifi- 
cation after the manner of Comes and Anastasia cannot be relied upon 
unless supported by experimental evidence. 

2. An adequate scheme of classification should be based upon iden- 
tities and dissimilarities in the genotypes, irrespective of the derivation 
of the forms in question. 

3. Mendelian analysis in Tabacum requires that special attention 
be paid to residual portions of the genotype, so that the factor differ- 
ences under consideration act in a stable residuum most favorable for 
emphasis of the character differences under investigation. 


LITERATURE CITED 
ALLARD, H. A. 


1919. Some studies in blossom color inheritance in tobacco, with special 
reference to N. sylvestris and N. Tabacum. Am. Nat., vol. 53, pp. 
79-84, 
ANASTASIA, G. E. 
1906. Le varieta tipiche della Nicotiana Tabacum L. Scafati. 
BRIDGES, C. B. 
1919. Specific modifiers of eosin eye color in Drosophila melanogaster. Jour. 
Exp. Zool., vol. 28, pp. 337-384. 


1922 Setchell-Goodspeed-Clausen: Nicotiana Tabacum 521 


CastTLE, W. C. 
1919. Piebald rats and the theory of genes. Proc. Nat. Acad. Sci., vol. 4, 
pp. 126-130. 
COLLINS, G. N. 
1917. Hybrids of Zea ramosa and Zea tuncata. Jour. Agric. Res., vol. 9, 
pp. 383-396. 
ComEs, O. F 
1899. Monographie du genre Nicotiana comprenant le classement botanique 
des tabaes industriels. Atti del R. Instituto d’Incoraggiamento di 
Napoli, ser. V, vol. 1. 
1905. Dello razze dei tabacchi filogenesi, qualita ed uso. Ibid., vol. 57. 
Hast, HE. M. 
1913. Inheritance of flower size in crosses between Nicotiana species. Bot. 
Gaz., vol. 55, pp. 177-188. 
GOODSPEED, T. H. 
1912. Quantitative studies of inheritance in Nicotiana hybrids. Univ. Calif. 
Publ. Bot., vol. 5, pp. 87-168. 
GOODSPEED, T. H., and CLAUSEN, R. E. 
1917. The nature of the F, species hybrids between Nicotiana sylvestris and 
varieties of N. Tabacum. Univ. Calif. Publ. Bot., vol. 5, pp. 301-346. 
HARLAN, H. V. 
1918. The identification of varieties of barley. U.S. Dept. of Agric., Bull. 
622, pp. 1-32. 
Hayes, H. K. 
1912. Correlation and inheritance in Nicotiana Tabacum. Conn. Agric. Exp. 
Station, Bull. 171, pp. 1-45. 
Hayes, H. K., Hast, E. M., and Brernuart, E. G. 
1913. Tobacco breeding in Connecticut. Conn, Agric. Exp. Station, Bull. 
176, pp. 1-68. al _— 
HASSELBRING, isi 
1912. Types of Cuban tobacco. Bot. Gaz., vol. 53, pp. 113-126. 
Howarp, A., and Howarp, GABRIELLE L. C. 
1910. Studies in Indian tobaccos. No. 2, The types of Nicotiana Tabacum L. 
Mem. India Dept. Agric. Bot. Series, vol. 3, pp. 59-176. 
How arp, GABRIELLE L. C. 
1913. Studies in Indian tobaccos. No. 3, The inheritance of characters in 
Nicotiana Tabacum L. Ibid., vol. 6, pp. 25-114. 
Muuter, H. J. 
1918. Genetic variability, twin hybrids, and constant hybrids in a case of 
balanced lethal factors. Genetics, vol. 3, pp. 422-499. 
Ripeway, ROBERT 
1912. Color standards and color nomenclature. 
SETCHELL, W. A. 
1912. Studies in Nicotiana, I. Univ. Calif. Publ. Bot., vol. 5, pp. 1-86. 
Waits, O. E. 
1913. Bearing of teratological development in Nicotiana on theories of 
heredity. Am. Nat., vol. 47, pp. 206-229. 
1914. The history of Nicotiana, II. An account of the heredity and envi- 
ronment of a family of tobacco plants. Brooklyn Bot. Garden 
Leaflets, Series 2, No. 12. 


EXPLANATION OF PLATES 


A special note is due the illustrations in this paper. The line drawings were 
made by Miss Anna Hamilton and Miss Helen M. Gilkey. Special attention was 
paid to accuracy in proportions and details. No attempt, however, was made 
to represent the characteristic Nicotiana pubescence. The photographs require 
no special mention save that sometimes the garden number given in thé legend 
does not correspond with that given on the label in the photograph. The dif- 
ference is due to a change in system of numbering used in F, and in subsequent 
populations. In this paper, in order to avoid confusion, garden numbers from 
the beginning have been made to conform to this change. The legends of 
all the plates have been made more complete than is usual in order to facilitate 
cross-reference and to enable the reader to grasp their essential significance more 
readily. 


PLATE 55 


Fig. 1. Nicotiana Tabacum var. angustifolia, U. C. B. G. 68/07. A typical 
plant of angustifolia at the height of its blooming period. The laterals over- 
topping the central* axis and the long-petioled stenophylla form of leaf are 
especially to be noted. The drooping of the leaves is very characteristic of this 
variety. 

Fig. 2. Nicotiana Tabacum var. macrophylla, U. C. B. G. 22/07. A typical 
plant of macrophylla at the height of its blooming period. Note especially the 
stout laterals overtopping the central axis and the sessilifolia type of leaf. 


[522] 


OA ‘(108 ‘1aNd ‘4IWVO UAINA 


fo) 
G 


[NS3SNV10-033dSG0059-113HOLSS | 


SG 31V1d 


PLATE 56 


Nicotiana Tabacum var. angustifolia, U. C. B. G. 68/07. Line drawings of 
typical details of angustifolia. In the upper right-hand corner the characteristic 
straplike sessile leaf or bract of the inflorescence. Upper left, details of bud, 
flower, and capsule. Lower right, details of pistil and stamens. Lower left, the 
typical long-petioled stenophylla leat of angustifolia. Leaves X 1%; flowers and 
capsules natural size. 


[524] 


56 


L-GOODSPEED-CLAUSEN] PLATE 


PUBEBOn, VOL. SRRESENCHEL 


UNIV, CALIF. 


PLATE 57 


Nicotiana Tabacum var. macrophylla, U. C. B. G. 22/07. Line drawings of 
typical details of a plant of macrophylla, showing floral details and the extreme 
variations in leaf size and shape on the plant. Leaves X 14; flowers and cap- 
sules natural size. 


[526] 


é . 
UNIV. CALIF. PUBL. BOT. VOL. 5 [SETCHELL-GOODSPEED-CLAUSEN] PLATE 57 


PLATE 58 


Fig. 1. Nicotiana Tabacum var. angustifolia, U. C. B. G. 68/07. Typical leaves 
of angustifolia of the stenophylla type showing the range of variation on a single 
plant. 

Fig. 2. Nicotiana Tabacum yar. macrophylla, U. C. B. G. 22/07. Typical leaves 
of macrophylla of the sessilifolia type showing the range of variation on a single 
plant. 


[528] 


[| SETCHELL-GOODSPEED-CLAUSEN ] PLATE 58 


UNIV, CALIF. PUBL. BOT. VOL. 5 


9 


ig. 1 Wig. 2 


PLATE 59 
Angustifolia-macrophylla series, F, leaves. 


Fig. 1. Typical leaf of 10F,H.P;, an F, of the angustifolia-macrophylla 
series. Note the short, winged petiole and the clasping auricles. 

Fig. 2. Typical leaf of 10F,H,P;.,, a variation from the usual latifolia -_ 
of the F, leaf. -Note the shorter petiole, less conspicuously winged condition, 
and the almost total lack of auricles. 

Fig. 3. Typical leaf of 10F,H,P,,. The petiole is somewhat longer than that 
normal for the F,. 

Fig. 4. Typical leaf of 10F,H;P;,. The petiole here is shorter than that 
normal for the F,. F 


VINIVG CARI: RUBE, BO, VOLES [ SETCHELL-GOOBSPEED-CLAUSEN] PLATE 59 


PLATE 60 


Portions of inflorescences of N. Tabacum var. macrophylla, N. Tabacum var. 
angustifolia and the F, hybrid between them. 

Fig. 1. Left, portion of inflorescence of macrophylla, middle, of the F,, and 
right, of angustifolia. 

Fig. 2. Left, portion of the inflorescence of macrophylla, middle, two of the 
F,, and right, of angustifolia. 


UNIV: CAEIEs (RUBE. BOT; VOE. 5 [SETCHELL-GOODSPEED-CEAUSEN] PEATE 60 


fy 
\ 


PLATE 61 
Angustifolia-macrophylla series, F, plants. 


Fig. 1. Photograph of 10F,H,P,, the F, plant from which the leaf shown 
in plate 59, figure 1, was taken. ; ; 

Fig. 2. Photograph of 10F,H;P;,, the F, plant from which the leaf shown 
in plate 59, figure 4, was taken. 


[534] 


UNIVE (CABIA PUBEM BO MOET. S [ SETCHELL-GOODSPEED-CLAUSEN] PLATE 61 


PLATE 62 
Angustifolia-macrophylla series, line drawings of F,. 


Line drawings showing morphological details of the typical F, plant of the 
angustifolia-macrophylla series. The garden number of the plant was 10F,H,,P,. 
Leaves X 144; flowers and capsules natural size. 


[536 ] 


PeonUB esol, VOLE 6iaisenchiEELGOODSPEED-CEAUSEN ]) IREATE G2 


UNIV. CALI 


PLATE 63 
Angustifolia-macrophylla series, type 1. 


Line drawings of morphological details of F, of type 1. The garden number 
was 11F.H,P;Py. Note particularly the stenophylla type of leaf. Leaves X 14; 
flowers and capsules natural size. 

The F, progeny of this plant consisted of 16 stenophylla of type 1 and 9 lance- 
olata of type 14. 


[538] 


PLATE 64 
Angustifolia-macrophylla series, type 2. 


Line drawings of morphological details of F, of type 2. The garden number 
was 11F.H.P;P5.. The leaf is of the latifolia type. Leaves X 1%; flowers and 
capsules natural size. 

The F,; progeny of this plant consisted of 12 latifolia, 8 sessilifolia, and 4 
auriculata. 


[540 | 


UNIV. CALIF, PUBL. BOT. VOL. 5 [SETCHELL-GOODSPEED-CLAUSEN] PLATE 64 


PLATE 65 
Angustifolia-macrophylla series, type 3 


Line drawings of morphological details of F, of type 3. The garden number 
was 11F.H,P;P,, The leaf is of the latifolia type. Leaves X 14; flowers and 
capsules natural size. 


The F, progeny of this plant consisted of 4 latifolia and 10 sessilifolia. 


[542] 


UNIV. CALIF. PUBL: BOT. VOL. & [SETCHELL-GOODSPEED-CLAUSEN] PLATE 65 


PLATE 66 
Angustifolia-macrophylla series, type 4. 


Line drawings of the morphological details of type 4. The garden number 
was 11F.H,P;P,, The leaf is an extreme form of the latifolia type. Leaves 
x 14%; flowers and capsules natural size. 


No progeny was grown from this plant. 


[544] 


ATE 66 


] 


L-GOODSPEED-CLAUSEN 


ForPUBEmBOn. VOLE! ST SEnCHEL 


UNIV. CALI 


PLATE 67 
Angustifolia-macrophylla series, type 5. 


Line drawings of morphological details of type 5. The garden number was 
11F,H,P,,P,,. The leaf is of the latifolia type. Leaves X 4%; flowers and ecap- 
sules natural size. ’ : 


The F, progeny of this plant consisted of 24 latifolia and 1 auriculata. 


[546] 


UNIV. CALIF, PUBL. BOT. VOL. & [SETCHELL-GOODSPEED-CLAUSEN] PLATE 67 


PLATE 68 
Angustifolia-macrophylla series, type 6. f 


Line drawings of morphological details of F, of type 6. The garden number 
was 11F.H,P.P,. The leaf is of the latifolia type. Leaves X 14; flowers and 
capsules natural size. 

The F, progeny of this plant consisted of 5 stenophylla, 17 latifolia, and 4 
auriculata plants, but the segregation was not distinct. 


[548] 


PLATE 69 
Angustifolia-macrophylla series, type 7. 


Line drawings of morphological details of F, of type 7. The garden number 
was 11F,H.P,,P,;. The leaf is of the latifolia type. Leaves X 14; flowers and 
capsules natural size. 

The F, progeny of this plant was uniformly of the same type as the parent, 
and the line bred true in subsequent generations. 


[550] 


PLATE 70 
Angustifolia-macrophylla series, type 8. 


Line drawings of morphological details of F, of type 8. The garden number 
was 11F,H.P,P,,. The leaf approached the auriculata type. Leaves X %; 
flowers and capsules natural size. 

The F, progeny of this plant consisted of 16 sessilifolia and 8 auriculata, 
indicating that the F, plant was an extreme variant of the heterozygous sessilifolia- 
auriculata condition. 


UNIV. CALIF. PUBL: BOT. VOL. & [SETCHELL-GOODSPEED-CLAUSEN ] PLATE 70 


PLATE 71 
Angustifolia-macrophylla series, type 9. 


Line drawings of morphological details of F, of type 9. The garden number 
was 11F.H,P,,P;. The leaf is of the latifolia type. Leaves X 1%; flowers and 
capsules natural size. 


The F, progeny of this plant consisted of 18 latifolia and 7 sessilifolia. 


[554] 


UNIV. CALIF. PUBL. BOT. VOL. 5 [ SETCHELL-GOODSPEED-CLAUSEN ] PLATE 71 


. 


PLATE 72 
Angustifolia-macrophylla series, type 10. 


Line drawings of morphological details of F. of type 10. The garden number 
was 11F,H,P,Py. The leaf was of the auriculata type. Leaves X 1%; flowers 
and capsules natural size. 


The F, progeny of this plant consisted uniformly of awriculata plants. 


UNIV. CALIF, PUBL. BOT. VOL. 5 [SETCHELL-GOODSPEED-CLAUSEN ] PLATE 72 


PLATE 73 
Angustifolia-macrophylla series, type 11. 


Line drawings of morphological details of F, of type 11. The garden number 
was 11F,H,P,,P,. The leaf is of the sessilifolia type. Leaves X 14; flowers and 
capsules natural size. 


The F, progeny of this plant was uniformly of the same sessilifolia type. 


[558] 


UNIVCABIE, IZUBE BOT, VOLES)  [SENCHELL-GOODSPEED-CLEAUSEN ]) PEATE 73 


PLATE 74 
Angustifolia-macrophylla series, type 12. 
Line drawings of morphologica] details of F, of type 12. The garden number 
was 11F,H,P,,P,.. The leaf is of the loriifolia type. Leaves X 14; flowers and 
capsules natural size. 


The F, progeny of this plant was uniformly of the same loriifolia type, and 
two constant races, one with red and one with light pink flowers, were obtained 


from it. 


[560] 


UNIV: CALIF. PUBE. BOT. VOL. 5 [SETCHELL-GOODSPEED-CLAUSEN ] PLATE 74 


PLATE 75 
Angustifolia-macrophylla series, type 13. 


Line drawings of morphological details of F, of type 13. The garden number 
was 11F,H,P,P,,. The leaf is of the lanceolata type. Leaves X 1%; flowers and 


capsules natural size. 


The F, progeny of this plant was uniformly of the same lanceolata type. 


[562 | 


PLATE 76 
Angustifolia-macrophylla series, type 14. 


Line drawings of morphological details of F, of type 14. The garden number 
was 11F,H.P,P,,. The leaf was classified as sessilifolia, although strictly it is 
intermediate between sessilifolia and lanceolata. Leaves X 1%; flowers and 
capsules natural size. Fi 

The F, progeny of this plant consisted of 24 plants of the same sessilifolia 
type and 1 ‘‘filler,’?’ which had leaves more like auriculata of type 8. 


[564] 


PLATE 77 
Angustifolia-macrophylla series, type 15. 


Line drawings of morphological details of F, of type 15. The garden number 
was 11F,H.P;P,. The leaf is of the sessilifolia type. Leaves X 14; flowers and 
capsules natural size. 


The F,; progeny of this plant was uniformly of the same leaf type. 


[566] 


PLATE 78 
Angustifolia-macrophylla series, type 16. 


Line drawings of morphological details of F, of type 16. The garden number 
was 11F,H,P,P. The leaf is of the sessilifolia type. Leaves X 1%; flowers and 
capsules natural size. . 


The F, progeny of this plant consisted of 15 sessilifolia and 8 auriculata. 


[568 | 


PLATE 79 
Nicotiana Tabacum var. calycina, U. C. B. G. 110/05. 


Line drawings of morphological details of leaf and flower of calycina. The 
leaf is of the lanceolata type, and the flowers are of the conspicuously teratolog- 
ical, split hose-in-hose form. Leaves X 1%; flowers and capsules natural size. 


[570 | 


UNIV. CALIF, PUBL. BOT. VOL. & [SETCHELL-GOODSPEED-CLAUSEN ] PLATE 79 


PLATE 80 
Nicotiana Tabacum vay. virginica, U. C. B. G. 78/05. 


Line drawings of morphological details of leaf and flower of virginica. Con- 
trast the normal flowers and auricled leaves with the corresponding details of 
calycina, shown in plate 79. Leaves X 4; flowers and capsules natural size. 


[572] 


UNIV CALI PUBEm BOT, VOLE 6 i SERCHELLGOODSPEED-CLAUSEN ] REATE 80 


[574] 


PLATE 82 
Nicotiana Tabacum var. alba, U. C. B. G. 30/06. 
Line drawings of morphological details of flower and leaf of alba. Note 
especially the rugose leaf. Compare this drawing with those of macrophylla 


shown in plates 57 and 58, figure 2. Leaves K 14; flowers and capsule natural 
size. 


VOL, 5S /SERCHEEL-GOODSPEED-CLAUSEN ] PLATE je2 


UNIV. CALIF, PUBL. BOT. 


‘ophylla series. The 


ae pr 
“2 


Tae 


phylla series, an F, ] 


[578 


LATE 83 


UNIV. CALIF. PUBL. BOT. VOL. 5 [ SETCHELL-GOODSPEED-CLAUSEN ] PLATE 883 


Fig. 1 


Fig. 1. 
Fig. 2. 


series. 


Fig. 3. 


series. 


PLATE 84 
Alba-macrophylla series, F, leaves. 
Photograph of typical leaves of alba. 


Photograph of a typical leaf of 10F,H,,P,;, F, of the alba-marcophylla 


Photograph of a typical leaf of 10F,H.,P;,, F, of the alba-macrophylla 


Compare these leaves with those of macrophylla, shown in plate 58, figure 2. 
The rugoseness of alba has been carried over, to a somewhat reduced extent, into 
the F, hybrid. 


[580] 


“3 
Ol 


G 


‘108 “‘1ENd ‘SIIVO ‘AINA 


“TOA 


=i} 


G 


[ NSSNV10-G33dSGOOD-113HOLSS | 


v8 3LV1d 


ith 


PLATE 85 


Fig. 1. Alba-macrophylla series, F, plants. Photograph of two adjacent 
plants, 11F,H.,P;,P.. and 11F,H.,P,,P.,, from the same F, population of the alba- 
macrophylla series. An illustration of segregation for height in this population. 

Fig. 2. Alba-macrophylla series, an F, plant. Photograph of a typical F, 
plant, 13F,H.,P,,P.,P.P., of a dwarf line of the alba-macrophylla series. The 
line here illustrated was derived from the dwarf F, plant shown in figure 1. This 
line has bred true for seven generations. 


[582] 


UNIV. CALIF. PUBL, BOT. 


~~ 


_ UNIVERSITY OF CeTEORNER Spek oe Caartacenme i, 


1914-1919. 


» 1. Parasitic Florideae, by William Albert ‘Setchell. Pp. 1-34, ‘Plates 1-6, 
etre BUGS aS ce eee fp RO eso ae POD YE Med oh Oo RS NE a PRC 


"2. Phytomorula pe dealin a Symmetrical Protophyte Related to Coclastrum, by 


Charles Atwood Kofoid, Pp. 35-40, plate 7. “April, 1914°- 0 


“8. Variation in. Oenothera ovata, by Katherine Layne Brandegee. Fp. 41-50, 


i gDAGUEB Bods UNO. AO Aaa cess es, aot peeen Mere ae ce Nig taunt Ua ae Ne 


c 4: Plantae sabe diel ores Purpusianae. VI by Some Stith Brandegee. “Pp. 


oR RS aS GN Pi Me a Seana eas a es Ope en ae OSL Po Ree par RUE ete ee ca 


5. The Scinaia Assemblage, “by William.Albert Setchell. Pp. 79- 152; plates 
BAUS 6 BR ced Or Lot) Pie SCN WSUS SR ee AN tae RS RE co rege Me Dice era eS Oe OO 


6. Notes on Pacific Coast Algae. ne Pylaictta Postelsiae, n. sp., a New. Type’ in 
the Genus Pylaielia, by Carl SEOe BEE. Pe: 153-164, piates 17-19, - May, 
DS ine ee Pres Ege ae aN ge eee Shae ae ge Nia SY Bs ea 


7, New and N oteworthy Californian Plants, Il, by Harvey Monroe Hall. Pp. 


165-176, plate 20; October, 1915 27 Fe ee a eS 


, 8, Plantae Mexicanae Purpusianae, VII, by Townshend Stith Brandegee. Pp: 


Bie Floral Relations among. the Galapagos Islands, by A. LL. Kroeber. . Pp: ; 


199-220. March, 42 AREER ve Se OU Pat Sep coe a aince 7 ro URS Meme Oe Some NN 

10. The Comparative Histology of Certain Californian Boletaceae, by Harry S.: 
Vates. Pp; 221-274, plates 21-25, - February,.1916.. 2-02. a. 

11, A Revision of the Tuberales of California, by Helen Margaret Gilkey. eP 
275-356, plates: 26-30, March, 0986 Gen Se a ee Se 

ii 12. Species Novae vel Minus Cognitae, by T.S. Brandegee. Pp. 357-361. May, 
Gee GS eS a A Ae ROMS UE Fab ceh sae yl Une ea ean UN OUR RIOD tomo 

18, Plantae Mexicanae Purpusianae. VIII, by Townshend Stith Brandegee. 
Pp. 263-875.- March, 1917-0000. Pele Renoir srchs GI poh ARC Meera eRe ey ae RD 

- 14. New Pacific Coast Marine Algae. I, by Nathaniel Lyon Gardner. Pp, 377- 
EO ASPB 3} eH Gh fs 3 redo Pager SE bet = pent AU Wy co a Se pee nO ceo NU RUCN RC eI ele ecrn a NS 

15. An Account of the Mode of» Foliar Abscission in Citrus, by Robert. W. 
Hodgson. Pp. 417-428, 3 text figures. -February, 1918 2.220 k 

16. New Pacific Coast Marine Algae, II, by Nathaniel Lyon Gardner. Pp. 429- 
Pe ROMA LAUDS SOradd fy) DULY 5 ADL OS oi od. esl wth wctct Larue Seoe essa sostto a a Reebe= sos N ce ponoa cote 


DU VOd cis OELODEE AGH i Si Nee ae ais ele ere On Ce a 


‘17, New Pacific.Coast Marine Algae. III, by Nathaniel Iiyon Gardner. Pp. 


455-486, plates 38-41... December, 1918 2.2......-) nnn i ete eli ceesdes 


© 18, New Pacific Coast Marine Algae. IV, by Nathaniel Lyon Gardner. ~Pp. 


AGT-S96; Wate: 42 WAMU ys BOLO ci ee Oe eh a ee tS 


- 19. Plantae Mexicanae Purpusianae. IX, by Townshend Stith Brandegee, Pp. 


‘Vol. 7. 
” 4. ‘Notes on the Californian Species of Trillium L. I, A Report of the General 


497-504, MPOVOMIOY, SOLD cic a iPect wo caer i eaten eat ueitagi® A eae 
Index in preparation. 


1916-, 


Results of Field and Garden Studies, 1911-1916; by Thomas Harper Good- 
speed and Robert Percy Brandt, Pp. 1-24, plates 1-4; October, 1916........ 


2. Notes on the Californian Species of Trillium L. II, The Nature and Occur- 
rence of Undeveloped Flowers, by Thomas Harper Goodspeed: and Robert 
Percy Brandt. Pp. 25-38, plates 5-6. October, 1916 .2.uoe ee 


oi, 8, Notes on the Californian Species of Trillium lL. III, Seasonal Changes in 


Trillium Species with Special Reference to the Reproductive Tissues, by 
Robert Percy Brandt. Pp. 39-68, plates 7-10. December, 1916 ..... 


4, Notes on the Californian Species of Trillium L. IV, Teratological Varia- 
tions of Trillium sessile var. giganteum H, & A., by Thomas Harper Good- 
speed, Pp. 69-100, plates 11-17. January, 1917 2.2.02. o cece eee ateeeeeeeee 


a ‘i 


oe 
UNIVERSITY OF CALIFORNIA susapnas ues ; 


6. A Preliminary List of the Uredinales of California, by Walter C. Staaae 
Pp. 101-157. August, 1919 5 . 


6, 7, 8. A Rubber Plant Survey of Western North America. L Chrysothamnus aes Se eee 
nauseosus and Its Varieties, by Harvey Monroe Hall. II. Chrysi,a New = =. 
Rubber from Chrysothamnus nauseosus, by Harvey Monroe Hall and ~-- = = 
Thomas Harper Goodspeed. III. The Occurrence of Rubber in Certain — 
West American Shrubs, by Harvey Monroe Hall and Thomas Harper = = : 
Goodspeed. Pp. 159-278, plates 18-20, 8 figures in text. November, 1919. 225 0 ¢ 2 


9. Phycological Contributions. I, by William Albert Setchell and Nathaniel te 
Lyon Gardner. Pp. 279-324, plates 21-31. April, 1920 ..:.cc----eccecsecesnecssocene ~. 60 


10. Plantae Mexicanae Purpusianae. X, by Townshend “ Brandegee. Fp. is c 
825-331. “December, 1920 onan. ccnececeencdecocersadanensancedlfleeccoosanenssnenenrsbsuneers 10- ae 
Vol. 8, 1919-, eS pes tee ne: 
1. The Marine Algae of the Pacific Coast of North Amentas gee L perce tans 
Myxophyceae, by William Albert Setchell and Nathaniel Lyon Gardner. pee es 

Pp. 1-138, plates 1-8. November, 1919 ...cc.ccocccccecceccectscescccsuseccns-cesscenonpertuncesenceee ee 


2. The Marine Algae of the Pacific Coast of North America. Part Ree Pas ee 
Chlorophyceae, by William Albert Setchell and Nathaniel Lyon Gardner, © 2 
Pp. 139-374, plates 9-33. July, 1920 


Son ene cnt ecatestencereeesennessuscacatooserwarasaeetnvanesnereseeree A ee 


Vol. 9. A Report upon the Boreal Flora of the Sierra Nevada of passe by Frank - 


Jason Smiley. Pp. 1-423, plates 1-7. October, OQD s.escecceccccccccecetneeeneen 5.0 pHs 
Vol. 10, 1922. Be ee a 
1. The Genus Fucus on the Pacific Coast of North America, by Nathaniel Lyon 2 

rc hoot sean aah Sh i se ies ib on MPP Ue tanya nahh n= Sash Sohn ees Waser anes TUR ee aes anime GEM press) 


